arm: at91: dt: sam9g20ek: use rts/cts/dtr/dsr/dcd/ri pinctrl group for uart0

Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

arch/arm/boot/dts/at91sam9g20ek_common.dtsi

@@ -35,6 +35,12 @@
 			};
 
 			usart0: serial@fffb0000 {
+				pinctrl-0 =
+					<&pinctrl_uart0
+					 &pinctrl_uart0_rts_cts
+					 &pinctrl_uart0_dtr_dsr
+					 &pinctrl_uart0_dcd
+					 &pinctrl_uart0_ri>;
 				status = "okay";
 			};