ARM: dts: msm: Update the pet time NS WDOG on msm8937

10 second timer have granularity at 640ms for HZ == 100.
Update the pet time to account for the timer inaccuracy.

Change-Id: I40398348c27c976d72726ef42adb753543476c17
Signed-off-by: Maria Yu <aiquny@codeaurora.org>