thermal: qcom-spmi-temp-alarm: enable stage 2 shutdown when required

Certain TEMP_ALARM GEN2 PMIC peripherals need over-temperature
stage 2 automatic PMIC partial shutdown to be enabled in order to
avoid repeated faults in the event of reaching over-temperature
stage 3.  Modify the stage 2 shutdown control logic to ensure that
stage 2 shutdown is enabled on all affected PMICs.  Read the
digital major and minor revision registers to identify these
PMICs.

Change-Id: Ieefbd4c9478f99d407da5ff12df593d56cbc1092
Signed-off-by: David Collins <collinsd@codeaurora.org>