After the state is committed, we readout the HW registers and compare
the HW state with the SW state that we just committed.
For Transcdoer port sync, we add master_transcoder and the
salves bitmask to the crtc_state, hence we need to read those during
the HW state readout to avoid pipe state mismatch.

v11:
* Move master trans init to get pipe_Config hooks (Ville)
v10:
* Initialize master_tarnscoder readout for all platforms (Ville)
v9:
* Initialize master_transcoder = INVALID at get config (Ville)
v8:
* Use master_select -1, address TRANS_EDP case (Ville)
* Rename master_transcoder to _readout (Lucas)
v7:
* NDont read HW state for DSI
v6:
* Go through both parts of HW readout (Maarten)
* Add a WARN if the same trans configured as
master and slave (Ville, Maarten)
v5:
* Add return INVALID in defaut case (Maarten)
v4:
* Get power domains in master loop for get_config (Ville)
v3:
* Add TRANSCODER_D (Maarten)
* v3 Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
v2:
* Add Transcoder_D and MISSING_CASE (Maarten)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191018172725.1338-3-manasi.d.navare@intel.com