OMAP3: PM: Remove PER wakeup dependency on CORE.

We can remove this wakeup dependency since now, when
GPIO2-6 are enabled for IO-pad wakeup, PER domain is gauranteed
to be awake or be woken up to service.

The previous dependency did not handle all corner cases. Since there
was no sleep dependency between CORE and PER domains, if PER enters
RET and CORE is ON, PER will not be active for GPIO handling.

Signed-off-by: Mike Chan <mike@android.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>