arm64: dts: exynos: gs101: switch to gs101 specific reboot

gs101 (Google Pixel 6 and Pixel 6 Pro) supports cold- and warm-reboot.
Cold-reset is useful because it is more secure, e.g. wiping all RAM
contents, while the warm-reboot allows RAM contents to be retained
across the reboot, e.g. to collect potential crash information.

Add the required DT changes to switch to the gs101-specific reboot
method, which knows how to issue either reset as requested by the OS.

The PMIC plays a role in this as well, so mark it as
'system-power-controller', which in this case ensures that the device
will wake up again after a cold-reboot, ensuring the full power-cycle
is successful.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250627-gs101-reboot3-v1-3-c3ae49657b1f@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Author: andred

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

@@ -106,6 +106,7 @@
 		interrupts-extended = <&gpa0 6 IRQ_TYPE_LEVEL_LOW>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&pmic_int>;
+		system-power-controller;
 		wakeup-source;
 
 		regulators {

arch/arm64/boot/dts/exynos/google/gs101.dtsi

@@ -1419,10 +1419,7 @@
 			};
 
 			reboot: syscon-reboot {
-				compatible = "syscon-reboot";
-				offset = <0x3a00>; /* SYSTEM_CONFIGURATION */
-				mask = <0x2>; /* SWRESET_SYSTEM */
-				value = <0x2>; /* reset value */
+				compatible = "google,gs101-reboot";
 			};
 
 			reboot-mode {