ARM: dts: msm: Update MDP Writeback QoS configuration for msm8916

Right now, Writeback QoS registers are being programmed dynamically
when respective paths are being exercised. Program these registers
as part of mdp hw settings to avoid configmon failures.

Change-Id: Ia06c5283541a734e8de81814cf3e5e083a4964e6
Signed-off-by: Vishnuvardhan Prodduturi <vproddut@codeaurora.org>