arm64: dts: meson-g12a-x96-max: fix compatible

This fixes the following DT schemas check errors:
meson-g12a-x96-max.dt.yaml: /: compatible: ['amediatech,x96-max', 'amlogic,u200', 'amlogic,g12a'] is not valid under any of the given schemas
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-g12a-x96-max.dts

@@ -11,7 +11,7 @@
 #include <dt-bindings/sound/meson-g12a-tohdmitx.h>
 
 / {
-	compatible = "amediatech,x96-max", "amlogic,u200", "amlogic,g12a";
+	compatible = "amediatech,x96-max", "amlogic,g12a";
 	model = "Shenzhen Amediatech Technology Co., Ltd X96 Max";
 
 	aliases {