ARM64: dts: meson-axg: remove vddio_ao18 from SoC dtsi

Regulator should not be defined inside the SoC dtsi file.
vddio_ao18 is already defined in the S400 board dts anyway.

Fixes: bb8a2ebd0498 ("ARM64: dts: meson-axg: add saradc support")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-axg.dtsi

@@ -91,13 +91,6 @@ psci {
 		method = "smc";
 	};
 
-	vddio_ao18: regulator-vddio_ao18 {
-		compatible = "regulator-fixed";
-		regulator-name = "VDDIO_AO18";
-		regulator-min-microvolt = <1800000>;
-		regulator-max-microvolt = <1800000>;
-	};
-
 	timer {
 		compatible = "arm,armv8-timer";
 		interrupts = <GIC_PPI 13