ARM: dts: msm: Update the pet time NS WDOG on msm8953

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

Change-Id: I66d10a5a6160777c5f413e730474a241d9f900c8
Signed-off-by: Maria Yu <aiquny@codeaurora.org>