ARM: dts: aspeed: yosemite4: adjust secondary flash name

Meta (Facebook) has a preference for all of our secondary flash
chips to be labelled "alt-bmc" for consistency of userspace tools
deal with updates.  Bletchley, Harma, Minerva, and Catalina all
follow this convention but for some reason Yosemite4 is different.

Adjust the label in the dts to match the other platforms.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Link: https://patch.msgid.link/20250107162726.232402-1-patrick@stwcx.xyz
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite4.dts

@@ -159,7 +159,7 @@
 	flash@1 {
 		status = "okay";
 		m25p,fast-read;
-		label = "bmc2";
+		label = "alt-bmc";
 		spi-tx-bus-width = <2>;
 		spi-rx-bus-width = <2>;
 		spi-max-frequency = <50000000>;