media: dt-bindings: media: nxp,imx7-mipi-csi2: Add i.MX8MM support

The i.MX8MM integrates a newer version of the CSIS CSI-2 receiver as the
i.MX7 family. Differences in integration are are:

- An additional clock is required
- Up to 4 data lanes are supported
- No reset or PHY supply is present

Support it in the DT binding.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>