ARM: dts: am437x-gp-evm: Add pinmux for uart0

Add pinmux for rx,tx,cts and rts lines of uart0. This will enable uart0
to use hardware flow control.
Signed-off-by: NVignesh R <vigneshr@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am437x-gp-evm.dts

@@ -501,6 +501,21 @@
 			AM4372_IOPAD(0x884, PIN_INPUT_PULLDOWN | MUX_MODE7) /* gpmc_csn2.gpio1_31 */
 		>;
 	};
+
+	uart0_pins_default: uart0_pins_default {
+		pinctrl-single,pins = <
+			AM4372_IOPAD(0x968, PIN_INPUT | MUX_MODE0)		/* uart0_ctsn.uart0_ctsn */
+			AM4372_IOPAD(0x96C, PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* uart0_rtsn.uart0_rtsn */
+			AM4372_IOPAD(0x970, PIN_INPUT_PULLUP | MUX_MODE0)	/* uart0_rxd.uart0_rxd */
+			AM4372_IOPAD(0x974, PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* uart0_txd.uart0_txd */
+		>;
+	};
+};
+
+&uart0 {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart0_pins_default>;
 };
 
 &i2c0 {