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 <daniel@makrotopia.org>