arm64: dts: exynos: gs101-pixel-common: add main PMIC node

On Pixel 6 (and Pro), a Samsung S2MPG10 is used as main PMIC, which
contains the following functional blocks:
    * common / speedy interface
    * regulators
    * 3 clock outputs
    * RTC
    * power meters
    * GPIO interfaces

This change enables the PMIC itself and the RTC. We're still working on
the remaining parts or waiting for bindings to be merged, hence only a
small subset of the functional is being enabled.

The regulators fall into the same category (still being finalised), but
since the binding requires a 'regulators' node, an empty node is being
added to avoid validation errors at this stage.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250627-gs101-reboot3-v1-2-c3ae49657b1f@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Author: andred

arch/arm64/boot/dts/exynos/google/gs101-pixel-common.dtsi

@@ -100,6 +100,19 @@
 	};
 };
 
+&acpm_ipc {
+	pmic {
+		compatible = "samsung,s2mpg10-pmic";
+		interrupts-extended = <&gpa0 6 IRQ_TYPE_LEVEL_LOW>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pmic_int>;
+		wakeup-source;
+
+		regulators {
+		};
+	};
+};
+
 &ext_24_5m {
 	clock-frequency = <24576000>;
 };
@@ -290,6 +303,12 @@
 };
 
 &pinctrl_gpio_alive {
+	pmic_int: pmic-int-pins {
+		samsung,pins = "gpa0-6";
+		samsung,pin-function = <GS101_PIN_FUNC_EINT>;
+		samsung,pin-pud = <GS101_PIN_PULL_NONE>;
+	};
+
 	key_power: key-power-pins {
 		samsung,pins = "gpa10-1";
 		samsung,pin-function = <GS101_PIN_FUNC_EINT>;