rockchip: dts: rk3399-puma: add /config/sysreset-gpio property

On the RK3399-Q7, we want to trigger a full platform reset (so the
various software stacks supported don't have to deal with the same
complexities over and over again) in case that anything other than a
power-on reset occurred.

To do so, this defines the /config/sysreset-gpio property and has it
point to a GPIO that will perform a power-on reset of the entire
platform.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Klaus Goger <klaus.goger@theobroma-systems.com>
diff --git a/arch/arm/dts/rk3399-puma.dtsi b/arch/arm/dts/rk3399-puma.dtsi
index 0f5e6ac..d2c961e 100644
--- a/arch/arm/dts/rk3399-puma.dtsi
+++ b/arch/arm/dts/rk3399-puma.dtsi
@@ -16,6 +16,7 @@
 		u-boot,mmc-env-offset = <0x4000>;      /* @  16KB */
 		u-boot,efi-partition-entries-offset = <0x200000>; /* 2MB */
 		u-boot,boot-led = "module_led";
+		sysreset-gpio = <&gpio1 RK_PA6 GPIO_ACTIVE_HIGH>;
 	};
 
 	chosen {
@@ -551,6 +552,10 @@
 	status = "okay";
 };
 
+&gpio1 {
+	u-boot,dm-pre-reloc;
+};
+
 &gpio3 {
 	u-boot,dm-pre-reloc;
 };