[legal] Add a selection of FILE_LICENCE declarations

Add FILE_LICENCE declarations to almost all files that make up the
various standard builds of gPXE.
diff --git a/src/interface/efi/efi_console.c b/src/interface/efi/efi_console.c
index b78de61..04af28a 100644
--- a/src/interface/efi/efi_console.c
+++ b/src/interface/efi/efi_console.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stddef.h>
 #include <assert.h>
 #include <gpxe/efi/efi.h>
diff --git a/src/interface/efi/efi_init.c b/src/interface/efi/efi_init.c
index 43a3ca8..ad55037 100644
--- a/src/interface/efi/efi_init.c
+++ b/src/interface/efi/efi_init.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <string.h>
 #include <gpxe/efi/efi.h>
 #include <gpxe/uuid.h>
diff --git a/src/interface/efi/efi_io.c b/src/interface/efi/efi_io.c
index e11f9bf..0ba16f8 100644
--- a/src/interface/efi/efi_io.c
+++ b/src/interface/efi/efi_io.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <assert.h>
 #include <gpxe/io.h>
 #include <gpxe/efi/efi.h>
diff --git a/src/interface/efi/efi_pci.c b/src/interface/efi/efi_pci.c
index f87b540..ec43391 100644
--- a/src/interface/efi/efi_pci.c
+++ b/src/interface/efi/efi_pci.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <errno.h>
 #include <gpxe/pci.h>
 #include <gpxe/efi/efi.h>
diff --git a/src/interface/efi/efi_smbios.c b/src/interface/efi/efi_smbios.c
index 5888f2f..8caf624 100644
--- a/src/interface/efi/efi_smbios.c
+++ b/src/interface/efi/efi_smbios.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <errno.h>
 #include <gpxe/smbios.h>
 #include <gpxe/efi/efi.h>
diff --git a/src/interface/efi/efi_snp.c b/src/interface/efi/efi_snp.c
index 771b917..e4b3546 100644
--- a/src/interface/efi/efi_snp.c
+++ b/src/interface/efi/efi_snp.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
diff --git a/src/interface/efi/efi_strerror.c b/src/interface/efi/efi_strerror.c
index adfeaed..2bf4581 100644
--- a/src/interface/efi/efi_strerror.c
+++ b/src/interface/efi/efi_strerror.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stdio.h>
 #include <gpxe/efi/efi.h>
 
diff --git a/src/interface/efi/efi_timer.c b/src/interface/efi/efi_timer.c
index d1ba43a..0dcb760 100644
--- a/src/interface/efi/efi_timer.c
+++ b/src/interface/efi/efi_timer.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <limits.h>
 #include <assert.h>
 #include <unistd.h>
diff --git a/src/interface/efi/efi_uaccess.c b/src/interface/efi/efi_uaccess.c
index 1c54c03..63e9521 100644
--- a/src/interface/efi/efi_uaccess.c
+++ b/src/interface/efi/efi_uaccess.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <gpxe/uaccess.h>
 #include <gpxe/efi/efi.h>
 
diff --git a/src/interface/efi/efi_umalloc.c b/src/interface/efi/efi_umalloc.c
index 4de3789..7113c79 100644
--- a/src/interface/efi/efi_umalloc.c
+++ b/src/interface/efi/efi_umalloc.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <assert.h>
 #include <gpxe/umalloc.h>
 #include <gpxe/efi/efi.h>
diff --git a/src/interface/smbios/smbios.c b/src/interface/smbios/smbios.c
index 8207c1f..cc7df59 100644
--- a/src/interface/smbios/smbios.c
+++ b/src/interface/smbios/smbios.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stdint.h>
 #include <string.h>
 #include <errno.h>
diff --git a/src/interface/smbios/smbios_settings.c b/src/interface/smbios/smbios_settings.c
index ec594c5..2235d49 100644
--- a/src/interface/smbios/smbios_settings.c
+++ b/src/interface/smbios/smbios_settings.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stdint.h>
 #include <string.h>
 #include <errno.h>