nvmem: Adding bindings for rockchip-efuse

There are some SoC specified values store in eFuse,
such as the cpu_leakage and cpu_version,
this driver can expose these values to /sys base on nvmem.

Signed-off-by: Caesar Wang <caesar.wang@rock-chips.com>
Signed-off-by: ZhengShunQian <zhengsq@rock-chips.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>