Refactor Flash/EEPROM reading code to use vtable with pointers to
small, specialized functions based on the flash class instead of big
monolithic funtions whose behaviour is driven by a number of flags and
variables.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>