drm/msm/sde: reset bw/clk control after crtc disable

Bandwidth & clock control are enabled if either crtc
properties are updated. Bandwidth & clock control
will stay enabled even after crtc is disabled and
re-enabled subsequently. This will force crtc to use
last commanded bandwidth & clock after re-enabled.
Instead, crtc should reset bandwidth & clock control
after disabled so that crtc can use default bandwidth
& clock setting after re-enabled.

CRs-Fixed: 2048612
Change-Id: I486b961eb9a50069e47f7f39fdba3298177ba456
Signed-off-by: Alan Kwong <akwong@codeaurora.org>