drm/bridge: tc358767: Wrap (e)DP aux I2C registration into tc_aux_link_setup()

drm/bridge: tc358767: Wrap (e)DP aux I2C registration into tc_aux_link_setup()

This bit of code is (e)DP and aux I2C link specific, move it into
tc_aux_link_setup() to permit cleaner addition of DSI-to-DPI mode.
No functional change.

Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Lucas Stach <l.stach@pengutronix.de> # In both DPI to eDP and DSI to DPI mode.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220329085015.39159-8-marex@denx.de