serial: meson: Update compatible with new Linux bindings

The Amlogic Meson SoCs serial bindings were not written when serial
support was pushed into Linux and U-Boot.
A clean bindings document has been merged into Linux tree to correctly
handle the multiple clocks feeding the serial peripheral.
This update the U-Boot serial_meson driver with the new compatible
string for Amlogic Meson GX Socs.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/serial_meson.c b/drivers/serial/serial_meson.c
index 363affb..6412ca6 100644
--- a/drivers/serial/serial_meson.c
+++ b/drivers/serial/serial_meson.c
@@ -125,6 +125,7 @@
 
 static const struct udevice_id meson_serial_ids[] = {
 	{ .compatible = "amlogic,meson-uart" },
+	{ .compatible = "amlogic,meson-gx-uart" },
 	{ }
 };