drm/i915: Use macro in place of open-coded for_each_universal_plane loop

This was the only use of (misleadingly-named) intel_num_planes()
function, so we can remove it as well.
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477522291-10874-3-git-send-email-matthew.d.roper@intel.comReviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>

drivers/gpu/drm/i915/intel_drv.h

@@ -1108,15 +1108,6 @@ hdmi_to_dig_port(struct intel_hdmi *intel_hdmi)
 	return container_of(intel_hdmi, struct intel_digital_port, hdmi);
 }
 
-/*
- * Returns the number of planes for this pipe, ie the number of sprites + 1
- * (primary plane). This doesn't count the cursor plane then.
- */
-static inline unsigned int intel_num_planes(struct intel_crtc *crtc)
-{
-	return INTEL_INFO(crtc->base.dev)->num_sprites[crtc->pipe] + 1;
-}
-
 /* intel_fifo_underrun.c */
 bool intel_set_cpu_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
 					   enum pipe pipe, bool enable);

drivers/gpu/drm/i915/intel_pm.c

@@ -4232,7 +4232,7 @@ static void skl_update_wm(struct drm_crtc *crtc)
 	if (crtc->state->active_changed) {
 		int plane;
 
-		for (plane = 0; plane < intel_num_planes(intel_crtc); plane++)
+		for_each_universal_plane(dev_priv, pipe, plane)
 			skl_write_plane_wm(intel_crtc, &pipe_wm->planes[plane],
 					   &results->ddb, plane);