arm64: dts: stratix10: socdk: drop unneeded flash address/size-cells

Flash node uses single "partition" node to describe partitions, so
remove deprecated address/size-cells properties to also fix dtc W=1
warnings:

  socfpga_stratix10_socdk.dts:182.10-211.4: Warning (avoid_unnecessary_addr_size): /soc@0/spi@ff8d2000/flash@0: unnecessary #address-cells/#size-cells without "ranges" or child "reg" property
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dts

@@ -180,8 +180,6 @@ rtc@68 {
 &qspi {
 	status = "okay";
 	flash@0 {
-		#address-cells = <1>;
-		#size-cells = <1>;
 		compatible = "micron,mt25qu02g", "jedec,spi-nor";
 		reg = <0>;
 		spi-max-frequency = <100000000>;