disp: msm: dsi: avoid panel mode switch flag after deep sleep

This change updates the checks needed before setting the flag
to enable panel switching between command and video mode.
New crtc active state remains disabled and it causes a failure
in the previous case.

Change-Id: I059731d2faa0f7844d3784fcf7694509fbba3ff7
Signed-off-by: Samantha Tran <samtran@codeaurora.org>