mediatek: 6.12: fix wrong SoC compatible of MT7988A RFB

The MediaTek MT7988A RFB currently hangs on boot as CCI fails to probe.
This is due to the wrong SoC compatible string "mediatek,mt7988" instead of
"mediatek,mt7988a". Fix that.

Fixes: f9206d1111 ("kernel/mediatek: 6.12: replace downstream files by patches")
Signed-off-by: Daniel Golle <[email protected]>

target/linux/mediatek/patches-6.12/188-arm64-dts-mediatek-add-MT7988A-reference-board-devic.patch

@@ -744,7 +744,7 @@ Signed-off-by: Daniel Golle <[email protected]>
 +/ {
 +	model = "MediaTek MT7988A Reference Board";
 +	compatible = "mediatek,mt7988a-rfb",
-+		     "mediatek,mt7988";
++		     "mediatek,mt7988a";
 +
 +	chosen {
 +		bootargs = "console=ttyS0,115200n1 loglevel=8  \