x86: seperate probe_roms into another file

it is only needed for 32bit

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/setup.h b/include/asm-x86/setup.h
index b434bdd..cf87d6d 100644
--- a/include/asm-x86/setup.h
+++ b/include/asm-x86/setup.h
@@ -54,6 +54,7 @@
 #ifdef __i386__
 
 void __init i386_start_kernel(void);
+extern void probe_roms(void);
 
 extern unsigned long init_pg_tables_start;
 extern unsigned long init_pg_tables_end;