drm/rockchip: vop: restore vop registers when resume

The registers will be reset to default values when whole
power domain off, so restore registers from regsbak.
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -496,6 +496,7 @@ static void vop_enable(struct drm_crtc *crtc)
 		goto err_disable_aclk;
 	}
 
+	memcpy(vop->regs, vop->regsbak, vop->len);
 	/*
 	 * At here, vop clock & iommu is enable, R/W vop regs would be safe.
 	 */