drm/i915: Simplify pipe_mask setup even further

Just set pipe_mask=~0 for the non-special cases where any pipe
will do. intel_encoder_possible_crtcs() will anyway drop out
anything that doesn't exist.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191002162505.30716-5-ville.syrjala@linux.intel.com


Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>