disp: msm: sde: reset crtc core perf while entering idle state

After coming out of idle state, bus vote is governed only
if there any change in perf compared to before entering idle
state. If the perf is same before and after the idle state,
bus update request is not considered and min bus votes are
voted. This change resets crtc core perf while entering
idle state always in command mode.

Change-Id: If172207422adc25fcee497aebe23aad1ac6ce7cc
Signed-off-by: Yashwanth <yvulapu@codeaurora.org>