mtd: rawnand: gpmi: Restore nfc timing setup after suspend/resume

As we reset the GPMI block at resume, the timing parameters setup by a
previous exec_op is lost.  Rewriting GPMI timing registers on first exec_op
after resume fixes the problem.

Fixes: ef347c0c

 ("mtd: rawnand: gpmi: Implement exec_op")
Cc: stable@vger.kernel.org
Signed-off-by: Esben Haabendal <esben@geanix.com>
Acked-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>