defconfigs: engicam: Enable UBI commands

defconfigs: engicam: Enable UBI commands

Create ubifs.img:
$ mkfs.ubifs -q -r /rootfs -m 4096 -e 253952 -c 7936 -o ubifs.img

Write ubifs.img:
---------------
icorem6qdl> nand erase.part rootfs
icorem6qdl> ubi part rootfs
icorem6qdl> ubi create rootfs

icorem6qdl> ext4load mmc 0:2 ${loadaddr} ubifs.img
166592512 bytes read in 8091 ms (19.6 MiB/s)
icorem6qdl> ubi write ${loadaddr} rootfs ${filesize}
166592512 bytes written to volume rootfs
icorem6qdl> ubifsmount ubi0:rootfs

Cc: Stefano Babic <[email protected]>
Cc: Matteo Lisi <[email protected]>
Cc: Michael Trimarchi <[email protected]>
Signed-off-by: Jagan Teki <[email protected]>