arm64: tegra: Add GPIO expanders on P2771

The P2771 development board expands the number of GPIOs via two I2C
chips.
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm64/boot/dts/nvidia/tegra186-p2771-0000.dts

@@ -18,6 +18,28 @@ power-monitor@43 {
 			compatible = "ti,ina3221";
 			reg = <0x43>;
 		};
+
+		exp1: gpio@74 {
+			compatible = "ti,tca9539";
+			reg = <0x74>;
+
+			interrupt-parent = <&gpio>;
+			interrupts = <TEGRA_MAIN_GPIO(Y, 0) GPIO_ACTIVE_LOW>;
+
+			#gpio-cells = <2>;
+			gpio-controller;
+		};
+
+		exp2: gpio@77 {
+			compatible = "ti,tca9539";
+			reg = <0x77>;
+
+			interrupt-parent = <&gpio>;
+			interrupts = <TEGRA_MAIN_GPIO(Y, 6) GPIO_ACTIVE_LOW>;
+
+			#gpio-cells = <2>;
+			gpio-controller;
+		};
 	};
 
 	/* SDMMC1 (SD/MMC) */