ARM: mvebu: armada-xp: Fix 74hc595 count for Lenovo ix4-300d

There is only one 74hc595 connected to GPIO but two were given
in the registers-number property. Fix it up.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-By: Benoit Masson <yahoo@perenite.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/armada-xp-lenovo-ix4-300d.dts

@@ -204,7 +204,7 @@ gpio_spi: gpio_spi@0 {
 			gpio-controller;
 			#gpio-cells = <2>;
 			reg = <0>;
-			registers-number = <2>;
+			registers-number = <1>;
 			spi-max-frequency = <100000>;
 		};
 	};