ARM: dts: msm: Support VADC_HC for mdmcalifornium

Clients can read supported thermistors from the VADC_HC
such as PA and XO therm, read voltage channels such as
vph_pwr input, coin cell input voltage, battery input
and PMIC die temperature.

Change-Id: I5870696b23160070c1229dadd0cffaaf46b20886
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>