drm/i915: Call g4x_find_best_dpll() directly from ILK+ code

The call to dev_priv->display.find_dpll() is already in platform
specific code, so avoid the extra detour.
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458576016-30348-5-git-send-email-ander.conselvan.de.oliveira@intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -8676,8 +8676,7 @@ static bool ironlake_compute_clocks(struct drm_crtc *crtc,
 	 * refclk, or FALSE.  The returned values represent the clock equation:
 	 * reflck * (5 * (m1 + 2) + (m2 + 2)) / (n + 2) / p1 / p2.
 	 */
-	ret = dev_priv->display.find_dpll(limit, crtc_state,
-					  crtc_state->port_clock,
+	ret = g4x_find_best_dpll(limit, crtc_state, crtc_state->port_clock,
 				 refclk, NULL, clock);
 	if (!ret)
 		return false;