ARM: dts: sun8i: Add touchscreen node for sun8i-a23-polaroid-mid2809pxe04

Add a node enabling the gsl3670 touchscreen controller found on
sun8i-a23-polaroid-mid2809pxe04 tablets.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>

arch/arm/boot/dts/sun8i-a23-polaroid-mid2809pxe04.dts

@@ -90,3 +90,12 @@ wifi_pwrseq_pin_mid2809: wifi_pwrseq_pin@0 {
 		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
 	};
 };
+
+&touchscreen {
+	reg = <0x40>;
+	compatible = "silead,gsl3670";
+	firmware-name = "gsl3670-polaroid-mid2809pxe04.fw";
+	touchscreen-size-x = <1660>;
+	touchscreen-size-y = <890>;
+	status = "okay";
+};