arm64: dts: amlogic: g12: bump spdif output drive strength

Spdif output currently uses a 0.5mA drive strength by default.
While the result depends on how the spdif output is hooked to
rest of the system, this is a bit weak and signal quality
may be poor. This was reported on the vim3l for example.

Increase the drive strength to 3mA, as used for TDM, to be on the
safe side.

Fixes: 649675db ("arm64: dts: meson: g12a: add spdifouts")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20240625115443.934763-1-jbrunet@baylibre.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>