[PATCH] ppc32: fix compilation error in include/asm/prom.h

make defconfig give the following error on ppc (gcc-4):

arch/ppc/syslib/prom_init.c:120: error: static declaration of ‘prom_display_paths’ follows non-static declaration
include/asm/prom.h:17: error: previous declaration of ‘prom_display_paths’ was here
arch/ppc/syslib/prom_init.c:122: error: static declaration of ‘prom_num_displays’ follows non-static declaration
include/asm/prom.h:18: error: previous declaration of ‘prom_num_displays’ was here

Signed-Off-By: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>