[PATCH] ppc64: Add missing include

inline pmac_call_feature references ppc_md so include asm/machdep.h
in asm/pmac_feature.h

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>