ARM: dts: msm: specify ADC channel for TEMP_ALARM devices on PM8150* PMICs

Specify the PMIC DIE_TEMP ADC channel for the TEMP_ALARM PMIC
peripheral devices found in PM8150, PM8150B, and PM8150L PMICs.
This ensures that clients can read the exact die temperature of
these PMICs at runtime instead of relying upon a very coarse
estimate based upon the over-temperature stage.

Change-Id: I8d2fee35fe3eb23405f2f6d41bc82045c80f55cf
Signed-off-by: David Collins <collinsd@codeaurora.org>