arm64: dts: imx8mp: Drop simple-bus from fsl,imx8mp-media-blk-ctrl

This block should not be compatible with simple-bus and misuse it that way.
Instead, the driver should scan its subnodes and bind drivers to them.

Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Liu Ying <victor.liu@nxp.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Fixes: 94e6197d ("arm64: dts: imx8mp: Add LCDIF2 & LDB nodes")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>