nvmem: add driver for Layerscape SFP (Security Fuse Processor)

Add support for the Security Fuse Processor found on Layerscape SoCs.
This driver implements basic read access.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151527.17216-10-srinivas.kandagatla@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>