drm/amd/display: Fix EDID parsing after resume from suspend

BugLink: https://bugs.launchpad.net/bugs/1904430

[Why]
Resuming from suspend, CEA blocks from EDID are not parsed and no video
modes can support YUV420. When this happens, output bpc cannot go over
8-bit with 4K modes on HDMI.

[How]
In amdgpu_dm_update_connector_after_detect(), drm_add_edid_modes() is
called after drm_connector_update_edid_property() to fully parse EDID
and update display info.

Cc: stable@vger.kernel.org
Signed-off-by: Stylon Wang <stylon.wang@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit b24bdc3)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Timo Aaltonen <timo.aaltonen@canonical.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -1948,6 +1948,7 @@ amdgpu_dm_update_connector_after_detect(struct amdgpu_dm_connector *aconnector)
 
 			drm_connector_update_edid_property(connector,
 							   aconnector->edid);
+			drm_add_edid_modes(connector, aconnector->edid);
 
 			if (aconnector->dc_link->aux_mode)
 				drm_dp_cec_set_edid(&aconnector->dm_dp_aux.aux,