arm64: dts: meson: g12a: add drive-strength hdmi ddc pins

With the default boot settings, the DDC drive strength is too weak,
set the driver-strengh to 4mA to avoid errors on the DDC line.
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.dtsi

@@ -290,6 +290,7 @@ mux {
 								 "hdmitx_sck";
 							function = "hdmitx";
 							bias-disable;
+							drive-strength-microamp = <4000>;
 						};
 					};