i.MX: ocotp: Move OCOTP driver to drivers/nvmem ...

Move OCOTP driver to drivers/nvmem to be consistent with Linux
kerenel.

Cc: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Tested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

nvmem: add snvs_lpgpr for freescale imx6 ...

SNVS LPGPR is Non Volatile Low Power Generic Purpose Register which
can be used as part of nvmem framework.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers: add nvmem framework from kernel ...

Add the nvmem framework from Linux.

Based on the v4.4-rc3 version.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>