arm/dt: msm-pm8941: Add temperature alarm device node

Add a temperature alarm device node for PM8941 so that the PMIC
die temperature may be monitored and so that an interrupt is
triggered if thermal overload occurs.

Change-Id: Ie0d6b0333dd45290bf7eb09c3fda616743b9373e
Signed-off-by: David Collins <collinsd@codeaurora.org>