ARM: dts: imx6q-pistachio: Use 'uart-has-rtscts' property

The 'fsl,uart-has-rtscts' property is deprecated and it is recommended
to use the generic 'uart-has-rtscts' property instead.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6q-pistachio.dts

@@ -614,7 +614,7 @@
 &uart5 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_uart5>;
-	fsl,uart-has-rtscts;
+	uart-has-rtscts;
 	status = "okay";
 };