ARM: dts: msm: enable dynamic fps for SDM670 on fhd panel

Enabling dynamic fps for nt35695b truly fhd dsi
video panel on sdm670. The feature helps to reduce fps
when static screen leading to power saving.

Change-Id: I1577c1273677eecc1e58bbb0c4adc80e51a5e6a5
Signed-off-by: Raviteja Tamatam <travitej@codeaurora.org>