arm64: dts: renesas: rzv2mevk2: Add uart0 pins

Add uart0 pins in pinctrl node and update the uart0 node
to include pinctrl and uart-has-rtscts properties.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230209131422.192941-1-biju.das.jz@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/r9a09g011-v2mevk2.dts

@@ -237,6 +237,13 @@ cd {
 			power-source = <1800>;
 		};
 	};
+
+	uart0_pins: uart0 {
+		pinmux = <RZV2M_PORT_PINMUX(3, 0, 2)>, /* UATX0 */
+			 <RZV2M_PORT_PINMUX(3, 1, 2)>, /* UARX0 */
+			 <RZV2M_PORT_PINMUX(3, 2, 2)>, /* UACTS0N */
+			 <RZV2M_PORT_PINMUX(3, 3, 2)>; /* UARTS0N */
+	};
 };
 
 &pwc {
@@ -258,6 +265,10 @@ &sdhi0 {
 };
 
 &uart0 {
+	pinctrl-0 = <&uart0_pins>;
+	pinctrl-names = "default";
+
+	uart-has-rtscts;
 	status = "okay";
 };