mmc-utils: add patch userdata enhance

Add command line parameter 'userdata enhance' which set Enhanced attribute
in User Data Area and Enhanced User Data Area size to max. amount of memory area
which can have enhanced attribute.
The 'userdata enhance' command is used to partition the entire memory as
User Data Area enhanced.
NOTE!  This command is a one-time programmable change.

Signed-off-by: Mario Schuknecht <mario.schuknecht@dresearch-fe.de>