nvmem: core: cleanup old eeprom compat entry attributes

file permission are derived based on various configs for
default nvmem sysfs file, reuse it to create the eeprom
compat file too.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200417121306.23121-1-srinivas.kandagatla@linaro.org


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