ARM: dts: msm: Add VADC and ADC_TM channel nodes

Clients of VADC and ADC_TM include reading voltage phone
power, system thermistors for thermal mitigation such as
pa_therm, case_therm, ambient_therm. Add the supported VADC
and ADC_TM channels nodes.

Change-Id: I4fdefe5aaeac72e5ad6ba7ae9c1cb8b931f725c2
Signed-off-by: Rama Krishna Phani A <rphani@codeaurora.org>