ARM: dts: msm: add apps watchdog entry for 8992

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

Change-Id: I3b0e306faacbd1b8f8460780ec90f50400104912
Signed-off-by: Shashank Mittal <mittals@codeaurora.org>