arm64: dts: apple: Add chassis-type property for Mac Pro

The tower and rack mount Mac Pro variants share the same .dts file and
are identical except for the chassis. There doesn't appear to be a
property in Apple's device tree to distinguish these two devices so use
"server" as chassis type which describes both if one doesn't look too
carefully.

Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
Link: https://patch.msgid.link/20260109-apple-dt-chassis-type-v1-3-c215503734c5@jannau.net
Signed-off-by: Sven Peter <sven@kernel.org>

Author: jannau

arch/arm64/boot/dts/apple/t6022-j180d.dts

@@ -15,6 +15,8 @@
 / {
 	compatible = "apple,j180d", "apple,t6022", "apple,arm-platform";
 	model = "Apple Mac Pro (M2 Ultra, 2023)";
+	chassis-type = "server";
+
 	aliases {
 		nvram = &nvram;
 		serial0 = &serial0;