drm/amd/display: Initialise encoder assignment when initialising dc_state

drm/amd/display: Initialise encoder assignment when initialising dc_state

BugLink: https://bugs.launchpad.net/bugs/1971417
[Why]
Link encoder assignment tracking variables need to be (re)initialised
whenever dc_state is (re)initialised. Otherwise variables used for
dynamic encoder assignment (especially the link encoder availability
pool) are out of sync with dc_state and future encoder assignments are
invalid.

[How]
Initialise encoder assignment variables when creating new dc_state
resource.

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7a47c8820a1d97e6cb5bcef6b65529f1389b0e13)
Signed-off-by: Koba Ko <koba.ko@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>