thermal: qpnp-temp-alarm: add support for GEN2 PMIC peripherals

Add support for the TEMP_ALARM GEN2 PMIC peripheral subtype.  The
GEN2 subtype adds clock rate control and defines an over
temperature state with hysteresis instead of stage in the status
register.  There are two GEN2 states corresponding to stages 1
and 2.

CRs-Fixed: 1019272
Change-Id: Ic4ad048259eb3a356333e0529d52f39c39fc915f
Signed-off-by: David Collins <collinsd@codeaurora.org>
[ansharma@codeaurora.org: Fix minor merge conflicts]
Signed-off-by: ansharma <ansharma@codeaurora.org>