msm: ext-buck-control: add external buck support driver

Based on the dt file entry enables the external buck support
for sending active set and sleep set votes to turn-on and turn-off
external buck by toggling a gpio when the system is going PC.

CRs-fixed: 568380
Change-Id: Ib8ccb7d8a5a264f30a9b0f365637e418c2f6332b
Signed-off-by: Anil kumar mamidala <amami@codeaurora.org>
3 files changed