[PATCH] drm/mipi-dsi: Fix detach call without attach

[Tony Lindgren]

* Tomi Valkeinen <tomi.valkeinen at ideasonboard.com> [230921 10:51]:
> mipi_dsi_host_unregister() will call two functions for all its DSI
> peripheral devices: mipi_dsi_detach() and mipi_dsi_device_unregister().
> The latter makes sense, as the device exists, but the former may be
> wrong as attach has not necessarily been done.
> 
> To fix this, track the attached state of the peripheral, and only detach
> from mipi_dsi_host_unregister() if the peripheral was attached.
> 
> Note that I have only tested this with a board with an i2c DSI
> peripheral, not with a "pure" DSI peripheral.

Thanks this fixes the deferred probe warning I've been seeing:

Tested-by: Tony Lindgren <tony at atomide.com>