ARM: sun8i: h3: add SY8113B regulator on Banana Pi M2 Zero board

Banana Pi M2 Zero board has a SY8113B regulator, which is controlled via
GPIO and capable of outputing 1.1V when the PL1 GPIO is set to output 0
or 1.1V when the PL6 GPIO is set to input or output 1, and the output is
the power supply of the ARM cores in H3 SoC.

Add the device tree node of this regulator and set the cpu's cpu-supply
property to it.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dts

@@ -48,6 +48,23 @@
 		};
 	};
 
+	reg_vdd_cpux: vdd-cpux-regulator {
+		compatible = "regulator-gpio";
+		regulator-name = "vdd-cpux";
+		regulator-type = "voltage";
+		regulator-boot-on;
+		regulator-always-on;
+		regulator-min-microvolt = <1100000>;
+		regulator-max-microvolt = <1300000>;
+		regulator-ramp-delay = <50>; /* 4ms */
+
+		gpios = <&r_pio 0 1 GPIO_ACTIVE_HIGH>; /* PL1 */
+		enable-active-high;
+		gpios-states = <0x1>;
+		states = <1100000 0x0
+			  1300000 0x1>;
+	};
+
 	wifi_pwrseq: wifi_pwrseq {
 		compatible = "mmc-pwrseq-simple";
 		pinctrl-names = "default";
@@ -55,6 +72,10 @@
 	};
 };
 
+&cpu0 {
+	cpu-supply = <&reg_vdd_cpux>;
+};
+
 &ehci0 {
 	status = "okay";
 };