[efi] Remove redundant EFI_BOOT_FILE definitions

As of commit 79c0173 ("[build] Create util/genfsimg for building
filesystem-based images"), the EFI boot file name for each CPU
architecture is defined within the genfsimg script itself, rather than
being passed in as a Makefile parameter.

Remove the now-redundant Makefile definitions for EFI_BOOT_FILE.

Reported-by: Christian I. Nilsson <nikize@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
diff --git a/src/arch/arm32/Makefile.efi b/src/arch/arm32/Makefile.efi
index d720f34..9bd3438 100644
--- a/src/arch/arm32/Makefile.efi
+++ b/src/arch/arm32/Makefile.efi
@@ -8,10 +8,6 @@
 #
 ELF2EFI		= $(ELF2EFI32)
 
-# Specify EFI boot file
-#
-EFI_BOOT_FILE	= bootarm.efi
-
 # Include generic EFI Makefile
 #
 MAKEDEPS	+= arch/arm/Makefile.efi
diff --git a/src/arch/arm64/Makefile.efi b/src/arch/arm64/Makefile.efi
index 998a64d..96f2953 100644
--- a/src/arch/arm64/Makefile.efi
+++ b/src/arch/arm64/Makefile.efi
@@ -4,10 +4,6 @@
 #
 ELF2EFI		= $(ELF2EFI64)
 
-# Specify EFI boot file
-#
-EFI_BOOT_FILE	= bootaa64.efi
-
 # Include generic EFI Makefile
 #
 MAKEDEPS	+= arch/arm/Makefile.efi
diff --git a/src/arch/i386/Makefile.efi b/src/arch/i386/Makefile.efi
index 37ede65..aa809eb 100644
--- a/src/arch/i386/Makefile.efi
+++ b/src/arch/i386/Makefile.efi
@@ -8,10 +8,6 @@
 #
 CFLAGS		+= -malign-double
 
-# Specify EFI boot file
-#
-EFI_BOOT_FILE	= bootia32.efi
-
 # Include generic EFI Makefile
 #
 MAKEDEPS	+= arch/x86/Makefile.efi
diff --git a/src/arch/loong64/Makefile.efi b/src/arch/loong64/Makefile.efi
index 1c51bcd..611c910 100644
--- a/src/arch/loong64/Makefile.efi
+++ b/src/arch/loong64/Makefile.efi
@@ -4,10 +4,6 @@
 #
 ELF2EFI		= $(ELF2EFI64)
 
-# Specify EFI boot file
-#
-EFI_BOOT_FILE	= bootloongarch64.efi
-
 # Include generic EFI Makefile
 #
 MAKEDEPS	+= Makefile.efi
diff --git a/src/arch/riscv32/Makefile.efi b/src/arch/riscv32/Makefile.efi
index db83c8c..2cc1a93 100644
--- a/src/arch/riscv32/Makefile.efi
+++ b/src/arch/riscv32/Makefile.efi
@@ -4,10 +4,6 @@
 #
 ELF2EFI		= $(ELF2EFI32)
 
-# Specify EFI boot file
-#
-EFI_BOOT_FILE	= bootriscv32.efi
-
 # Include generic EFI Makefile
 #
 MAKEDEPS	+= arch/riscv/Makefile.efi
diff --git a/src/arch/riscv64/Makefile.efi b/src/arch/riscv64/Makefile.efi
index b19e036..3948ca1 100644
--- a/src/arch/riscv64/Makefile.efi
+++ b/src/arch/riscv64/Makefile.efi
@@ -4,10 +4,6 @@
 #
 ELF2EFI		= $(ELF2EFI64)
 
-# Specify EFI boot file
-#
-EFI_BOOT_FILE	= bootriscv64.efi
-
 # Include generic EFI Makefile
 #
 MAKEDEPS	+= arch/riscv/Makefile.efi
diff --git a/src/arch/x86_64/Makefile.efi b/src/arch/x86_64/Makefile.efi
index 0041bb8..f383756 100644
--- a/src/arch/x86_64/Makefile.efi
+++ b/src/arch/x86_64/Makefile.efi
@@ -12,10 +12,6 @@
 #
 ELF2EFI		= $(ELF2EFI64)
 
-# Specify EFI boot file
-#
-EFI_BOOT_FILE	= bootx64.efi
-
 # Include generic EFI Makefile
 #
 MAKEDEPS	+= arch/x86/Makefile.efi