drm/i915/adl_s: Initialize display for ADL-S

drm/i915/adl_s: Initialize display for ADL-S

Initialize display outputs for ADL-S. ADL-S has 5 display
outputs -> 1 eDP, 2 HDMI and 2 DP++ outputs.

v2:
- Use PORT_TCx instead of PORT_D,E.. to stay consistent
  with other platforms.(mdroper)

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210125140753.347998-8-aditya.swarup@intel.com