arm64: dts: meson-gx: fix watchdog compatible

This fixes the following DT schemas check errors:
meson-gxbb-nanopi-k2.dt.yaml: watchdog@98d0: compatible:0: 'amlogic,meson-gx-wdt' is not one of ['amlogic,meson-gxbb-wdt']
meson-gxl-s805x-libretech-ac.dt.yaml: watchdog@98d0: compatible:0: 'amlogic,meson-gx-wdt' is not one of ['amlogic,meson-gxbb-wdt']
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-gx.dtsi

@@ -325,7 +325,7 @@ spifc: spi@8c80 {
 			};
 
 			watchdog@98d0 {
-				compatible = "amlogic,meson-gx-wdt", "amlogic,meson-gxbb-wdt";
+				compatible = "amlogic,meson-gxbb-wdt";
 				reg = <0x0 0x098d0 0x0 0x10>;
 				clocks = <&xtal>;
 			};