uboot-imx

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>