i2c/chips: Move max6875 to drivers/misc/eeprom

This driver only reads the user EEPROM of that chip, so we can move it
to the eeprom-directory in order to further clean up (and later remove)
drivers/i2c/chips.

The Kconfig text was updated to match the current functionality,
dropping the meanwhile obsoleted parts.

Defconfigs have been adapted.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Ben Gardner <gardner.ben@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>