ARM: dts: am57xx: sbc-am57x: add GPIO expander support

Add PCA9555 GPIO expander support (over I2C5 bus).

Signed-off-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am57xx-sbc-am57x.dts

@@ -89,4 +89,11 @@
 		reg = <0x50>;
 		pagesize = <16>;
 	};
+
+	pca9555: pca9555@20 {
+		compatible = "nxp,pca9555";
+		reg = <0x20>;
+		gpio-controller;
+		#gpio-cells = <2>;
+	};
 };