drm/msm/sde: correct the CTL reset sequence in writeback path

In CTL reset sequence, after WB_ACTIVE removed from the data
path and flushed, wait for wb frame done is called leading to
timeout. Made changes to execute the CTL reset sequence for
MDP 5.0 only when has_3d_merge_reset is defined in MDP capabilities.
Legacy path remains unmodified and does not take effect when
has_3d_merge_reset is not defined. As has_3d_merge_reset is specific
to 5.0 MDP it is defined for SM6150 target as well.

Change-Id: I5ef4f92935a862241f517fc82eca944f130567cf
Signed-off-by: Raviteja Tamatam <travitej@codeaurora.org>