drm/msm/sde: avoid connector state mode update in commit thread

There is a race condition where connector state mode info is updated
in sde_encoder_virt_mode_set in crtc_commit thread and mode info
getting copied to new connector state in connector_atomic_duplicate_state
in hwbinder thread. This is causing new connector state to be in
invalid state leading to wrong dsc config and further leading
to ping pong timeouts.
Removed connector state mode info update in crtc_commit thread as
connector state mode info is updated in mode_fixup and does not need
updation in sde_encoder_virt_mode_set in crtc_commit thread.

Change-Id: If4d1b9581e287ffd1c414729249993922dc1b3ea
Signed-off-by: Raviteja Tamatam <travitej@codeaurora.org>