Revert "drm/bridge: imx: Add LDB support for i.MX8qm"

commit 0d2e9f527f0f46524a42fba591b99c1925c37d26 from
https://github.com/nxp-imx/linux-imx



As our downstream i.MX8qm LDB encoder driver module name conflicts with
the upstream i.MX8qm LDB bridge driver module name, revert the upstream
driver for now to avoid build break.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>