mtd: nand: raw: Port another option flag from Linux

Introduced in upstream Linux with commit 7a08dbaedd365 for release v5.0.

When the new atmel nand driver was backported to U-Boot with commit
6a8dfd57 ("nand: atmel: Add DM based NAND driver") that definition
was added to the driver instead of the header file.  Move it over to the
other definitions with the same help text it has in Linux.

Code actually using this has not been ported over to raw nand base yet.

Link: https://lore.kernel.org/all/20240320090214.40465-3-ada@thorsis.com


Signed-off-by: Alexander Dahl <ada@thorsis.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>