arm64: zynqmp: Describe ethernet controllers via aliases on SOM

Add ethernet aliases to CC (Carrier card) description to create a
connection which is used by U-BOOT (fdt_fixup_ethernet()) for updating
local-mac-address in DT.
On Kria SOM MAC address is read from i2c eeprom at start and based on it
environment variables are created. Without creating aliases U-Boot is not
able to inject local-mac-address DT property and OS won't get the same MAC
address unless another i2c read is happening in OS.
Also aliases are using string not phandle (because of dtso) that's why full
path has to be provided but that shouldn't be a big issue because location
of ethernet controller is fixed.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/72304150f87fd5e3338e31e2be8cf5d29955cc02.1756799774.git.michal.simek@amd.com

arch/arm64/boot/dts/xilinx/zynqmp-sck-kr-g-revB.dtso

@@ -20,6 +20,11 @@
 		     "xlnx,zynqmp-sk-kr260", "xlnx,zynqmp";
 	model = "ZynqMP KR260 revB";
 
+	aliases {
+		ethernet0 = "/axi/ethernet@ff0b0000"; /* &gem0 */
+		ethernet1 = "/axi/ethernet@ff0c0000"; /* &gem1 */
+	};
+
 	ina260-u14 {
 		compatible = "iio-hwmon";
 		io-channels = <&u14 0>, <&u14 1>, <&u14 2>;

arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revA.dtso

@@ -28,6 +28,10 @@
 		     "xlnx,zynqmp-sk-kv260", "xlnx,zynqmp";
 	model = "ZynqMP KV260 revA";
 
+	aliases {
+		ethernet0 = "/axi/ethernet@ff0e0000"; /* &gem3 */
+	};
+
 	ina260-u14 {
 		compatible = "iio-hwmon";
 		io-channels = <&u14 0>, <&u14 1>, <&u14 2>;

arch/arm64/boot/dts/xilinx/zynqmp-sck-kv-g-revB.dtso

@@ -23,6 +23,10 @@
 		     "xlnx,zynqmp-sk-kv260", "xlnx,zynqmp";
 	model = "ZynqMP KV260 revB";
 
+	aliases {
+		ethernet0 = "/axi/ethernet@ff0e0000"; /* &gem3 */
+	};
+
 	ina260-u14 {
 		compatible = "iio-hwmon";
 		io-channels = <&u14 0>, <&u14 1>, <&u14 2>;