drm/amd/display: Add MST atomic routines

- Adding encoder atomic check to find vcpi slots for a connector
- Using DRM helper functions to calculate PBN
- Adding connector atomic check to release vcpi slots if connector
loses CRTC
- Calculate  PBN and VCPI slots only once during atomic
check and store them on crtc_state to eliminate
redundant calculation
- Call drm_dp_mst_atomic_check to verify validity of MST topology
during state atomic check

v2: squashed previous 3 separate patches, removed DSC PBN calculation,
and added PBN and VCPI slots properties to amdgpu connector

v3:
- moved vcpi_slots and pbn properties to dm_crtc_state and dc_stream_state
- updates stream's vcpi_slots and pbn on commit
- separated patch from the DSC MST series

v4:
- set vcpi_slots and pbn properties to dm_connector_state
- copy porperties from connector state on to crtc state

v5:
- keep the pbn and vcpi values only on connnector state
- added a void pointer to the stream state instead on two ints,
because dc_stream_state is OS agnostic. Pointer points to the
current dm_connector_state.

v6:
- Remove new param from stream

v7:
- Fix error with using max capable bpc

v8:
- squash in fix from Gustavo A. R. Silva

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -359,6 +359,8 @@ struct dm_connector_state {
 	bool underscan_enable;
 	bool freesync_capable;
 	uint8_t abm_level;
+	int vcpi_slots;
+	uint64_t pbn;
 };
 
 #define to_dm_connector_state(x)\