ARM: dts: msm: Update VADC channels

Update the channel number for APQ_THERM and SYS_THERM
for reading from AMUX1 and AMUX3 using 100k internal
pull-up respectively through the VADC.

Change-Id: Ic96a195363a92436be0c53708723ad945c475703
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>