ARM: dts: msm: Add ADC nodes for pmfalcon

Clients of VADC_HC and BTM include reading voltage phone
power, system thermistors for thermal mitigation such as
msm_therm, case_therm, XO therm. Round robin ADC (RRADC)
provides clients ability to read supported channels from
PMfalcon RRADC such as battery ID, battery thermistors,
DCIN and USBIN voltage and current. Add the supported VADC,
BTM and RR ADC channels for the msmfalcon platforms.

Change-Id: I1b8bf9762642e0af73d7ac7fa51c974b93fd4b31
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>