drm/bridge: tc358767: Split tc_set_video_mode() into common and (e)DP part

The tc_set_video_mode() sets up both common and (e)DP video mode settings of
the bridge chip. Split the function into tc_set_common_video_mode() to set
the common settings and tc_set_edp_video_mode() to set the (e)DP specific
settings. 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/20220329085015.39159-11-marex@denx.de