drm/bridge: ti-sn65dsi83: Add TI SN65DSI83 and SN65DSI84 driver

Add driver for TI SN65DSI83 Single-link DSI to Single-link LVDS bridge
and TI SN65DSI84 Single-link DSI to Dual-link or 2x Single-link LVDS
bridge. TI SN65DSI85 is unsupported due to lack of hardware to test on,
but easy to add.

The driver operates the chip via I2C bus. Currently the LVDS clock are
always derived from DSI clock lane, which is the usual mode of operation.
Support for clock from external oscillator is not implemented, but it is
easy to add if ever needed. Only RGB888 pixel format is implemented, the
LVDS666 is not supported, but could be added if needed.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Philippe Schenker <philippe.schenker@toradex.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Valentin Raevsky <valentin@compulab.co.il>
To: dri-devel@lists.freedesktop.org
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210607174258.16300-2-marex@denx.de