ARM: dts: msm: update default mdp clock for 120 fps on kona target

In certain cases of 120 fps boot up with continuous splash, the
default mdp clock set at max svs level is low and is causing underrun
till the first commit comes. Increasing the mdp default clock to max
nominal level will avoid this scenario.

Change-Id: Idf01db61e12f2672788e58f19271384c0ff8d97f