Add regmap-based read function and instead of using three different
read functions (standard, mac, serial) use just one and factor out the
read offset adjustment for mac and serial to at24_adjust_read_offset.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>