staging: pi433: overlay: Fix reg-related warnings

When running "scripts/dtc/dtc -@ -I dts -O dtb -o pi433-overlay.dtbo.1
drivers/staging/pi433/Documentation/devicetree/pi433-overlay.dts":

    drivers/staging/pi433/Documentation/devicetree/pi433-overlay.dts:13.12-15.6: Warning (unit_address_vs_reg): /fragment@0/__overlay__/spidev@0: node has a unit name, but no reg property
    drivers/staging/pi433/Documentation/devicetree/pi433-overlay.dts:17.12-19.6: Warning (unit_address_vs_reg): /fragment@0/__overlay__/spidev@1: node has a unit name, but no reg property

Add the missing "reg" properties to fix this.

    drivers/staging/pi433/Documentation/devicetree/pi433-overlay.dts:14.5-15: Warning (reg_format): /fragment@0/__overlay__/spidev@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
    drivers/staging/pi433/Documentation/devicetree/pi433-overlay.dts:19.5-15: Warning (reg_format): /fragment@0/__overlay__/spidev@1:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)

Add the missing "#{address,size}-cells" to fix this.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200221122133.32024-3-geert+renesas@glider.beSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/pi433/Documentation/devicetree/pi433-overlay.dts

@@ -8,13 +8,17 @@ / {
 	fragment@0 {
 		target = <&spi0>;
 		__overlay__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
 			status = "okay";
 
 			spidev@0{
+				reg = <0>;
 				status = "disabled";
 			};
 
 			spidev@1{
+				reg = <1>;
 				status = "disabled";
 			};
 		};