msm: Add QPNP support routines

QPNP is a SPMI based PMIC architecture developed by Qualcomm.
This library constitutes routines that should be necessary for
most, if not all QPNP based devices. The goal is to minimize the
amount of code duplication.

Change-Id: I0fddfcef88416bba488480d790d1cf361d9e67ac
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>