drm/i915: Track plane fifo sizes under intel_crtc

Track the plane fifo sizes under intel_crtc instead of under each
intel_plane. Avoids looping over the planes in a bunch of places,
and later we'll move this tracking into the crtc state properly.

v2: Nuke intel_plane_wm_parameters (Maarten)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170302171508.1666-3-ville.syrjala@linux.intel.com