ARM: dts: armada-385-turris-omnia: rename node in -u-boot.dtsi file

The SPI NOR flash node name in main device tree for Turris Omnia is
called `spi-nor@0`.

Rename node spi-flash@0 in Turris Omnia's -u-boot.dtsi file to spi-nor@0
so that U-Boot does not try to probe the same SPI NOR device multiple
times.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Stefan Roese <sr@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Pali Rohár <pali@kernel.org>

arch/arm/dts/armada-385-turris-omnia-u-boot.dtsi

@@ -41,10 +41,7 @@
 &spi0 {
 	u-boot,dm-pre-reloc;
 
-	spi-flash@0 {
-		compatible = "jedec,spi-nor";
-		reg = <0>;
-		spi-max-frequency = <40000000>;
+	spi-nor@0 {
 		u-boot,dm-pre-reloc;
 	};
 };