ARM: dts: msm: add apps watchdog entry for msmthorium

Add watchdog entry to device tree to enable configuring
the watchdog timer to cause barks and bites so as to detect
system hangs.

Change-Id: Ia77f83352781407c80a0a1ab7f1c63c148a3684d
Signed-off-by: Xiaogang Cui <xiaogang@codeaurora.org>