thermal: adc-tm: Add support for PMIC7 ADC_TM

Add support for PMIC7 ADC_TM peripheral in ADC_TM common driver files.
Add main ADC_TM driver file for PMIC7. As register offsets and SW flows
have changed significantly for ADC_TM due to ADC architecture change,
this new driver is required for ADC_TM on PMIC7.

Change-Id: I9211552317955c503b7287876e11cd161c37f706
Signed-off-by: Jishnu Prakash <jprakash@codeaurora.org>