OMAP3: PM: Removing redundant and potentially dangerous PRCM configration

As part of Core domain context restoration while coming out of off mode
there are some registers being restored which are not required to be restored.
ROM code will have restored them already. Overwriting some of them can have
potential side effect. Eg: CM_CLKEN_PLL register should not be written while dpll is locked.
Tested on OMAP 3430 SDP for suspend/resume and off mode with sleep_while_idle enabled.

Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>