ARM: dts: STiH410-b2260: Enable HW flow-control

Hardware flow-control capability must be specified at a platform
level in order to inform the ASC driver that the platform is capable
(i.e. are the lines wired up, etc).  STiH4{07,10} devices are indeed
capable, so let's provide the property.
Acked-by: NPeter Griffin <peter.griffin@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/boot/dts/stih410-b2260.dts

@@ -66,6 +66,7 @@
 			pinctrl-0 = <&pinctrl_serial0_hw_flowctrl>;
 			pinctrl-1 = <&pinctrl_serial0>;
 			rts-gpios = <&pio17 3 GPIO_ACTIVE_LOW>;
+			uart-has-rtscts;
 			status = "okay";
 		};