drm/amd/display: Do not update DRR while BW optimizations pending

[why]
While bandwidth optimizations are pending, it's possible a pstate change
will occur.  During this time, VSYNC handler should not also try to update
DRR parameters causing pstate hang

[how]
Do not adjust DRR if optimize bandwidth is set.

Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>