ARM: dts: lpc4357-ea4357: fix unit name warnings from dtc

Fix the following warnings from dtc by either adding or removing
the unit name from the node.

Warning (unit_address_vs_reg): Node /soc/flash-controller@40003000/flash@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_joystick/button@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_joystick/button@1 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_joystick/button@2 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_joystick/button@3 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /gpio_joystick/button@4 has a unit name, but no reg property

Signed-off-by: Joachim Eastwood <[e-mail]>

arch/arm/boot/dts/lpc4357-ea4357-devkit.dts

···
 		poll-interval = <100>;
 		autorepeat;
 
-		button@0 {
+		button0 {
 			label = "joy_enter";
 			linux,code = <KEY_ENTER>;
 			gpios = <&gpio LPC_GPIO(4,8) GPIO_ACTIVE_LOW>;
 		};
 
-		button@1 {
+		button1 {
 			label = "joy_left";
 			linux,code = <KEY_LEFT>;
 			gpios = <&gpio LPC_GPIO(4,9) GPIO_ACTIVE_LOW>;
 		};
 
-		button@2 {
+		button2 {
 			label = "joy_up";
 			linux,code = <KEY_UP>;
 			gpios = <&gpio LPC_GPIO(4,10) GPIO_ACTIVE_LOW>;
 		};
 
-		button@3 {
+		button3 {
 			label = "joy_right";
 			linux,code = <KEY_RIGHT>;
 			gpios = <&gpio LPC_GPIO(4,12) GPIO_ACTIVE_LOW>;
 		};
 
-		button@4 {
+		button4 {
 			label = "joy_down";
 			linux,code = <KEY_DOWN>;
 			gpios = <&gpio LPC_GPIO(4,13) GPIO_ACTIVE_LOW>;
···
 	pinctrl-names = "default";
 	pinctrl-0 = <&spifi_pins>;
 
-	flash@0 {
+	flash {
 		compatible = "jedec,spi-nor";
 		spi-cpol;
 		spi-cpha;