drm/amd/display: Reinit DPG when exiting dynamic ODM

[WHY]
DPG must be returned to initialized state when pipe is disabled.

[HOW]
Reinit DPG on unused pipes when exiting dynamic ODM.

Reviewed-by: Alvin Lee <Alvin.Lee2@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Dillon Varone <Dillon.Varone@amd.com>
Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>