msm: mdp3: Remove panic ctrl duing ctrl off

Panic ctrl is enabled on dma start and cleared
on dma stop, if supported. Doing the same again
in ctrl on/off is redundant.

Change-Id: I60dab92e54d01973fc11a3dc42933d1ab6f84a4e
Signed-off-by: Animesh Kishore <animeshk@codeaurora.org>