mtd: nand: add ONFI timing mode to nand_timings converter
Ported from Linux commit 974647e:
| Add a converter to retrieve NAND timings from an ONFI NAND timing mode.
| At the moment, only SDR NAND timings are supported.
|
| Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
| Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>