drm/mipi-dsi: Detach devices when removing the host

[ Upstream commit 668a8f17b5290d04ef7343636a5588a0692731a1 ]

Whenever the MIPI-DSI host is unregistered, the code of
mipi_dsi_host_unregister() loops over every device currently found on that
bus and will unregister it.

However, it doesn't detach it from the bus first, which leads to all kind
of resource leaks if the host wants to perform some clean up whenever a
device is detached.

Fixes: 068a0023 ("drm: Add MIPI DSI bus support")
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-2-maxime@cerno.tech


Signed-off-by: Sasha Levin <sashal@kernel.org>