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

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: I705818cde623d5bd818835ab7b498b1e3c5adf1a
Signed-off-by: Sarangdhar Joshi <spjoshi@codeaurora.org>