drm/amd/display: Clear sticky vsc sdp error bit

[Why]
Need to clear sticky error bits generated during hpd irq from receiver.

[How]
Clear sticky vsc sdp error bit.

Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>