power: qcom: apm: add support for apm drivers

Added apm drivers in order to keep backward compatibility
for cpr3 regulator. This snapshot is taken as of msm-4.4
'commit ae5acb1 (Merge "soc: msm-pcm: Add mutex lock to
protect prvt data")'.

Change-Id: If56c1ed27a901bc41c7b683b9aa29ee8f945e644
Signed-off-by: Asha Magadi Venkateshamurthy <amagad@codeaurora.org>