Increase EFI_STAGING_SIZE to 100MB on x64

To avoid failures when the large 18MB nvidia.ko module is being loaded,
increase EFI_STAGING_SIZE from 64MB to 100MB on x64 systems.
Leave the other platforms at 64MB.

stand/efi/loader/copy.c

@@ -176,8 +176,12 @@ efi_verify_staging_size(unsigned long *nr_pages)
 #endif /* __i386__ || __amd64__ */
 
 #ifndef EFI_STAGING_SIZE
+#if defined(__amd64__)
+#define	EFI_STAGING_SIZE	100
+#else
 #define	EFI_STAGING_SIZE	64
 #endif
+#endif
 
 EFI_PHYSICAL_ADDRESS	staging, staging_end;
 int			stage_offset_set = 0;