arm: msm: Select PM_OPP on MSM architectures

The Operating Power Point library provides a framework
for the storage and communication of frequency-to-voltage
tables between drivers and modules. Select it on MSM
architectures.

Change-Id: Ie9dea16fb6e762d59733208d84cca26ac0f9fd1b
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>