regulator: cpr-regulator: Add support for mem-acc regulator requests

The memory accelerator controls delays while accessing
memories. These delays vary based on the power-mode.
Provide the power-mode (corner) information from CPR
to the memory accelerator driver through the regulator
interface.

Change-Id: I9c13df1695d760aa7b4797f3ba5dc65590cf21e6
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>