DRM bridge drivers are now attaching their DSI device at probe time,
which requires us to register our DSI host in order to let the bridge
to probe: this recently started producing an endless -EPROBE_DEFER
loop on some machines that are using external bridges, like the
parade-ps8640, found on the ACER Chromebook R13.

Now that the DSI hosts/devices probe sequence is documented, we can
do adjustments to the mtk_dsi driver as to both fix now and make sure
to avoid this situation in the future: for this, following what is
documented in drm_bridge.c, move the mtk_dsi component_add() to the
mtk_dsi_ops.attach callback and delete it in the detach callback;
keeping in mind that we are registering a drm_bridge for our DSI,
which is only used/attached if the DSI Host is bound, it wouldn't
make sense to keep adding our bridge at probe time (as it would
be useless to have it if mtk_dsi_ops.attach() fails!), so also move
that one to the dsi host attach function (and remove it in detach).

Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>