arm64: dts: rockchip: add regulator info for Kevin digitizer

We need to enable this regulator before the digitizer can be used. Wacom
recommended waiting for 100 ms before talking to the HID.
Signed-off-by: Brian Norris <briannorris@chromium.org>
[store chip ident as comment until i2c multi-compatibles are sorted]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts

@@ -223,11 +223,15 @@ ap_i2c_dig: &i2c2 {
 	i2c-scl-rising-time-ns = <300>;
 
 	digitizer: digitizer@9 {
+		/* wacom,w9013 */
 		compatible = "hid-over-i2c";
 		reg = <0x9>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&cpu1_dig_irq_l &cpu1_dig_pdct_l>;
 
+		vdd-supply = <&p3_3v_dig>;
+		post-power-on-delay-ms = <100>;
+
 		interrupt-parent = <&gpio2>;
 		interrupts = <4 IRQ_TYPE_LEVEL_LOW>;