drm/amd/display: save restore hdcp state when display is unplugged from mst hub

[Why]
connector hdcp properties are lost after display is
unplgged from mst hub. connector is destroyed with
dm_dp_mst_connector_destroy. when display is plugged
back, hdcp is not desired and it wouldnt be enabled.

[How]
save hdcp properties into hdcp_work within
amdgpu_dm_atomic_commit_tail. If the same display is
plugged back with same display index, its hdcp
properties will be retrieved from hdcp_work within
dm_dp_mst_get_modes.

Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: hersen wu <hersenxs.wu@amd.com>
Reviewed-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>