Use relative path for bios

Look for bios and other support files relative to qemu binary, rather than
a hardcoded prefix.

Signed-off-by: Paul Brook <paul@codesourcery.com>
diff --git a/sysemu.h b/sysemu.h
index 92501ed..658aeec 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -10,7 +10,10 @@
 
 /* vl.c */
 extern const char *bios_name;
-extern const char *bios_dir;
+
+#define QEMU_FILE_TYPE_BIOS   0
+#define QEMU_FILE_TYPE_KEYMAP 1
+char *qemu_find_file(int type, const char *name);
 
 extern int vm_running;
 extern const char *qemu_name;