mtd: rawnand: timings: Fix default tR_max and tCCS_min timings

tR and tCCS are currently wrongly expressed in femtoseconds, while we
expect these values to be expressed in picoseconds. Set right
hardcoded values.

Fixes: 6a943386 mtd: rawnand: add default values for dynamic timings
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200428094302.14624-3-miquel.raynal@bootlin.com