ARM: dts: msm: Add phandle to read PMIC rev-id

The VADC/IADC peripheral need to read the PMIC type
and revision to apply the corresponding coefficients
for temperature compensation to vbatt and current.
The property is optional since there are few PMIC
VADC/IADC peripherals that don't have temperature
compensation coefficients added and during such
conditions the temprerature compensation is not
applied for those channels.

Change-Id: I5229934bec71b86f923042af943a3e080ceb009b
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>