drm/i915: Always use intel_get_crtc_for_pipe()

Replace the open coded dev_priv->pipe_to_crtc_mapping[] usage with
intel_get_crtc_for_pipe().

Mostly done with coccinelle, with a few manual tweaks

@@
expression E1, E2;
@@
(
- E1->pipe_to_crtc_mapping[E2]
+ intel_get_crtc_for_pipe(E1, E2)
|
- E1->plane_to_crtc_mapping[E2]
+ intel_get_crtc_for_plane(E1, E2)
)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-12-git-send-email-ville.syrjala@linux.intel.com


Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>