drm/amd/display: Release AUX engine after failed acquire

drm/amd/display: Release AUX engine after failed acquire

[Why]
There is a sequence in which aux arbitration
doesn't work correctly. Driver is left with
aux access after it times out waiting for access.
In future dmub fw is never granted aux access
and is stuck in a while loop.

[How]
Cancel aux request from driver after timing out.

Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>