USB: msm_otg: Add voting for sleep clock

USB PHY is provided sleep clock on few platform which is
required to enable for USB PHY functionality. Hence add
support to vote sleep clock if it exists.

CRs-Fixed: 518353
Change-Id: I67006bfe3fbe9b3ad3e1d1e2ddb0e8e060437bd7
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
2 files changed