drm/amd/display: dont wait for pipe update during medupdate/highirq

[why&how]
control flag for the wait during pipe update wait for vupdate should
be set if update type is not fast or med to prevent an invalid sleep
operation

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Ausef Yousof <Ausef.Yousof@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>