[PATCH] aoa: pmf gpio: report if function calling fails

This patch makes the pmf GPIO layer in aoa report if calling a platform
function failed.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>