arm64: dts: meson-gx: cec node should be disabled by default

This fixes the following DT schemas check errors:
meson-gxl-s905x-hwacom-amazetv.dt.yaml: cec@100: 'hdmi-phandle' is a required property
meson-gxm-rbox-pro.dt.yaml: cec@100: 'hdmi-phandle' is a required property

because CEC is not enabled on these boards.
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

@@ -392,6 +392,7 @@ cec_AO: cec@100 {
 				compatible = "amlogic,meson-gx-ao-cec";
 				reg = <0x0 0x00100 0x0 0x14>;
 				interrupts = <GIC_SPI 199 IRQ_TYPE_EDGE_RISING>;
+				status = "disabled";
 			};
 
 			sec_AO: ao-secure@140 {