arm: at91: dt: sam9m10g45ek: use rts/cts pinctrl group for uart1

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

arch/arm/boot/dts/at91sam9m10g45ek.dts

@@ -39,6 +39,7 @@
 			};
 
 			usart1: serial@fff90000 {
+				pinctrl-0 = <&pinctrl_uart0 &pinctrl_uart1_rts_cts>;
 				status = "okay";
 			};