drm/dsi: Use mipi_dsi_device_register_full() for DSI device creation

Use mipi_dsi_device_register_full() for device creation. This takes in
a struct mipi_dsi_device_info as a template to populate the DSI device
information.

The reason to introduce this is to have a way to create DSI devices not
available via DT. Drivers that want to create a DSI device can populate
a struct mipi_dsi_device_info and call this function. For DSI devices
available via DT, of_mipi_dsi_device_add() is used as before, but this
now calls mipi_dsi_device_register_full() internally.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>