disp: msm: sde: fix the QOS setting mismatch

Currently the display driver does not consider the write back
client while deriving client type for QOS settings.
Add new API to consider the write back and other non
real time clients also for picking up the proper QOS settings.
This patch also fixes the QOS setting mismatch with QSEEDLITE
hardware.

Change-Id: I5db3d21921b8930bb6399ea355d3ce2b60e51430
Signed-off-by: Lakshmi Narayana Kalavala <lkalaval@codeaurora.org>