ARM: dts: msm: Update the pet time NS WDOG on sdm670

As per the timer code on 4.9 kernel, the granularity for timer with
10 second expiry is 640ms. So if the NS wdog timer expiry is 10 the
worst case expiry for 10.64 seconds. Due the timer in accuracy there
could be false NS Wdog barks as this reduces time between pet and bark.
Update the pet time to account for the inaccuracy.

Change-Id: I1772f992399d5955e0f95338ece6af3d66166ff5
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>