drm/bridge: tc358767: Add DPI to eDP bridge driver

Add a drm_bridge driver for the Toshiba TC358767 DPI/DSI to
eDP/DP bridge. Currently only DPI input with 24-bit RGB is
supported.

Signed-off-by: Andrey Gusakov <andrey.gusakov@cogentembedded.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Archit Taneja <architt@codeaurora.org>