nvmem: rave-sp-eeprom: Add support for "zii,eeprom-name" ...

Upstream kernel driver allows specifying EEPROM name via
"zii,eeprom-name" property. Add code to support that in Barebox as
well.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

nvmem: rave-sp-eeprom: Remove VLA usage ...

This is a backport of patch [1] by Kees Cook

[1] https://lkml.kernel.org/r/20180620182600.GA24297@beast

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

nvmem: Port RAVE SP EEPROM driver from Linux kernel ...

This is a minimal port of a kernel commit 3b51f47be171 ("nvmem: Add
RAVE SP EEPROM driver"). All of the changes were kept to a minimum and
limited to impedance matching between Barebox/Linux driver API.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>