eeprom: Add bindings for simple eeprom framework

This patch adds bindings for simple eeprom framework which allows eeprom
consumers to talk to eeprom providers to get access to eeprom cell data.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[Maxime Ripard: intial version of eeprom framework]
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>