arm64: dts: meson: u200: use TDM C for HDMI

arm64: dts: meson: u200: use TDM C for HDMI

On the u200, TDM B is wired to the onboard AD82584F i2c speaker codec.
This makes TDM B a poor choice for the interface dedicated to HDMI which
uses 4 i2s lanes.

TDM A is not a good choice either as it is connected to the SDIO wifi/bt
chip.

TDM C is not used externally by default, which makes it a better choice for
the HDMI interface.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20230911154541.471484-5-jbrunet@baylibre.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>