ARM64: dts: meson-gx: remove unnecessary clocks properties

Since the switch to documented uart bindings, the clocks are
redefined in the SoC family dtsi file.

This patch removes these unneeded properties.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

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

@@ -228,7 +228,6 @@ uart_A: serial@84c0 {
 				compatible = "amlogic,meson-gx-uart", "amlogic,meson-uart";
 				reg = <0x0 0x84c0 0x0 0x14>;
 				interrupts = <GIC_SPI 26 IRQ_TYPE_EDGE_RISING>;
-				clocks = <&xtal>;
 				status = "disabled";
 			};
 
@@ -236,7 +235,6 @@ uart_B: serial@84dc {
 				compatible = "amlogic,meson-gx-uart", "amlogic,meson-uart";
 				reg = <0x0 0x84dc 0x0 0x14>;
 				interrupts = <GIC_SPI 75 IRQ_TYPE_EDGE_RISING>;
-				clocks = <&xtal>;
 				status = "disabled";
 			};
 
@@ -282,7 +280,6 @@ uart_C: serial@8700 {
 				compatible = "amlogic,meson-gx-uart", "amlogic,meson-uart";
 				reg = <0x0 0x8700 0x0 0x14>;
 				interrupts = <GIC_SPI 93 IRQ_TYPE_EDGE_RISING>;
-				clocks = <&xtal>;
 				status = "disabled";
 			};