drm/fsl-dcu: drop unused drm_crtc_index()

The result of drm_crtc_index() is unused. Remove the call and
the unused variable.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180926204150.29829-1-stefan@agner.ch

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c

@@ -85,9 +85,8 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
 	struct drm_connector *con = &fsl_dev->connector.base;
 	struct drm_display_mode *mode = &crtc->state->mode;
-	unsigned int hbp, hfp, hsw, vbp, vfp, vsw, index, pol = 0;
+	unsigned int hbp, hfp, hsw, vbp, vfp, vsw, pol = 0;
 
-	index = drm_crtc_index(crtc);
 	clk_set_rate(fsl_dev->pix_clk, mode->clock * 1000);
 
 	/* Configure timings: */