Remove obsolete BIOS_SIZE from sysemu.h

BIOS_SIZE is no longer needed by vl.c, so there's no point having it in
sysemu.h.

Signed-off-by: Paul Brook <paul@codesourcery.com>
diff --git a/hw/mips_mipssim.c b/hw/mips_mipssim.c
index 54656ad..b3f190e 100644
--- a/hw/mips_mipssim.c
+++ b/hw/mips_mipssim.c
@@ -31,12 +31,7 @@
 #include "net.h"
 #include "sysemu.h"
 #include "boards.h"
-
-#ifdef TARGET_WORDS_BIGENDIAN
-#define BIOS_FILENAME "mips_bios.bin"
-#else
-#define BIOS_FILENAME "mipsel_bios.bin"
-#endif
+#include "mips-bios.h"
 
 #ifdef TARGET_MIPS64
 #define PHYS_TO_VIRT(x) ((x) | ~0x7fffffffULL)