ARM: dts: meson8: Fix the UART device-tree schema validation

The dt-bindings for the UART controller only allow the following values
for Meson8 SoCs:
- "amlogic,meson8-uart", "amlogic,meson-ao-uart"
- "amlogic,meson8-uart"

Use the correct fallback compatible string "amlogic,meson-ao-uart" for
AO UART. Drop the "amlogic,meson-uart" compatible string from the EE
domain UART controllers.

Also update the order of the clocks to match the order defined in the
yaml schema.

Fixes: 6ca77502 ("ARM: dts: meson8: use stable UART bindings with correct gate clock")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20211227180026.4068352-3-martin.blumenstingl@googlemail.com