Datasheet:
https://www.winbond.com/resource-files/w25q32jv%20dtr%20revf%2002242017.pdf

Minimal testing done with fw_printenv/fw_setenv, test board did not
support dual or quad access.
Signed-off-by: NStephen Douthit <stephend@silicom-usa.com>
Tested-by: NStephen Douthit <stephend@silicom-usa.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@bootlin.com>