ARM: OMAP2+: Return correct error values from device and hwmod

Without this patch function pm_runtime_get_sync() returns 0 even when
some omap subfunction fails. This patch properly propagate error codes
from omap functions back to caller.

This patch fix problem, when loading omap-aes driver in qemu cause
kernel oops.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
[paul@pwsan.com: fix a checkpatch warning]
Signed-off-by: Paul Walmsley <paul@pwsan.com>