powerpc/microwatt: Fix model property in device tree

The standard property for the model name is called "model".

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250611-microwatt-v2-1-80847bbc5f9c@posteo.net

Author: neuschaefer

arch/powerpc/boot/dts/microwatt.dts

@@ -4,7 +4,7 @@
 / {
 	#size-cells = <0x02>;
 	#address-cells = <0x02>;
-	model-name = "microwatt";
+	model = "microwatt";
 	compatible = "microwatt-soc";
 
 	aliases {