drm/i915/dp_mst: Add the MST topology state for modesetted CRTCs

Add the MST topology for a CRTC to the atomic state if the driver
needs to force a modeset on the CRTC after the encoder compute config
functions are called.

Later the MST encoder's disable hook also adds the state, but that isn't
guaranteed to work (since in that hook getting the state may fail, which
can't be handled there). This should fix that, while a later patch fixes
the use of the MST state in the disable hook.

v2: Add missing forward struct declartions, caught by hdrtest.
v3: Factor out intel_dp_mst_add_topology_state_for_connector() used
    later in the patchset.

Cc: Lyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org # 6.1
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> # v2
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Lyude Paul <lyude@redhat.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230206114856.2665066-1-imre.deak@intel.com