[Why]
Screen flickering when HDR switches between FP16 and ARGB2101010

[How]
Moved pipe_control_lock so stream update and plane update occur atomically
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Signed-off-by: Lucy Li <lucy.li@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>