ARM: Use Kconfig for board EEPROM's I2C bus and chip address

In stead of defining the board EEPROM address in the board headers
let's define them in the board config files and make them
configurable by Kconfig.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>