drm/i915/display: Add HAS_D12_PLANE_MINIMIZATION

- As RKL and ADL-S only have 5 planes, primary and 4 sprites and
  the cursor plane, let's group the handling together under
  HAS_D12_PLANE_MINIMIZATION.
- Also use macro to select pipe irq fault error mask.

BSpec: 49251
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
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>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210129182945.217078-5-aditya.swarup@intel.com