layerscape: kernel: enable MC userspace support

layerscape: kernel: enable MC userspace support

Management Complex (MC) userspace support is required for userspace
helpers working with DPAA2 objects exported by the Management Complex BUS.

Without it, there is the error:

```
root@OpenWrt:/# ls-addni dpmac.1
error: Did not find a device file
Restool wrapper scripts only support the latest major MC version
that currently is MC10.x. Use with caution.
error: Did not find a device file
```

This patch fixes it.

Suggested-by: Alexandra Alth <alexandra@alth.de>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
(cherry picked from commit d04d6a82da70f6b691409972ffd4503f339105b7)