NAND: Add -y option to nand scrub command

NAND: Add -y option to nand scrub command

This allows the scrub command to scrub without asking the user if he really
wants to scrub the area. Useful in scripts.

Signed-off-by: Marek Vasut <[email protected]>
Cc: Scott Wood <[email protected]>
Cc: Stefano Babic <[email protected]>
Cc: Wolfgang Denk <[email protected]>
Cc: Detlev Zundel <[email protected]>
Acked-by: Mike Frysinger <[email protected]>
Signed-off-by: Scott Wood <[email protected]>