drm/imx: Don't set struct drm_device.irq_enabled

The field drm_device.irq_enabled is only used by legacy drivers
with userspace modesetting. Don't set it in imx.

v3:
	* move dcss changes into separate patch (Laurentiu)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625082222.3845-12-tzimmermann@suse.de

drivers/gpu/drm/imx/imx-drm-core.c

@@ -207,17 +207,6 @@ static int imx_drm_bind(struct device *dev)
 	if (IS_ERR(drm))
 		return PTR_ERR(drm);
 
-	/*
-	 * enable drm irq mode.
-	 * - with irq_enabled = true, we can use the vblank feature.
-	 *
-	 * P.S. note that we wouldn't use drm irq handler but
-	 *      just specific driver own one instead because
-	 *      drm framework supports only one irq handler and
-	 *      drivers can well take care of their interrupts
-	 */
-	drm->irq_enabled = true;
-
 	/*
 	 * set max width and height as default value(4096x4096).
 	 * this value would be used to check framebuffer size limitation