Revert "drm/bridge: adv7511: Attach to DSI host at probe time"

Revert "drm/bridge: adv7511: Attach to DSI host at probe time"

This reverts commit 69eb0e9a5568810bb843181a6e37b6099c45338f.

There are at least two DSI controller drivers which relies on the old
behaviour of adv7511 driver. To avoid platform breakage this patch
should be reverted. This is a temporary solution, as it blocks adv7511
usage with other platforms.
Assumption that DSI device driver (bridge/panel) should first expose
drm_bridge/drm_panel object, then look for DSI bus is just incorrect -
it can work with devices controlled via i2c but it cannot work with
devices controlled via DSI - they will not be able to probe.
To solve the issue following steps should be performed:
- rework reverted patch allowing co-operation with broken DSI controller
  drivers - with simple/ugly workaround,
- fix controller drivers and then remove workaround.

Signed-off-by: Rob Clark <robdclark@chromium.org>
[a.hajda: changed commit message]
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190829180836.14453-1-robdclark@gmail.com