mtd: rawnand: Stop using chip->state in drivers

We are about to simplify the locking in the rawnand framework, and part
of this simplication is about getting rid of chip->state, so let's
first patch drivers that check the state.

All of them do that to get a timeout value based on the operation that
is being executed. Since a timeout is, by definition, something that
is here to prevent hanging on an event that might never happen,
picking the maximum timeout value no matter the operation should be
harmless.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>