DRM: SDE: Fixing the power up sequence with early splash

If the splash clean up is trigger, the MDP core power on call should
be skipped.  MDP core already turned on in sde_kms_hw_init() if splash
handoff enabled.

Change-Id: Ie19c4eb2d0455b0c19615e3bb29aae4b4c6c8abf
Signed-off-by: Camus Wong <camusw@codeaurora.org>
Signed-off-by: Rahul Sharma <rahsha@codeaurora.org>
Signed-off-by: Suprith Malligere Shankaregowda <supgow@codeaurora.org>