cmd: mtd: print device OF path in listing

cmd: mtd: print device OF path in listing

Print MTD's device OF path in the output of `mtd list` command.

Signed-off-by: Marek Behún <[email protected]>
Reviewed-by: Miquel Raynal <[email protected]>
Tested-by: Patrice Chotard <[email protected]>
Reviewed-by: Jagan Teki <[email protected]>
Cc: Priyanka Jain <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Heiko Schocher <[email protected]>
Cc: Patrick Delaunay <[email protected]>