The phy is not in a useful state right after init. It will become useful,
including for auxiliary function such as CEC or ARC, after the first mode
is set. This is a problem on systems where the display is using another
interface like DSI or CVBS.

This change refactor the init and mode change callback to power up the PHY
on init and leave only what is necessary for mode changes in the related
function. This is enough to fix CEC operation when HDMI display is not
enabled.

Fixes: 3f68be7d ("drm/meson: Add support for HDMI encoder and DW-HDMI bridge + PHY")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240426160256.3089978-2-jbrunet@baylibre.comSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240426160256.3089978-2-jbrunet@baylibre.com