ARM: shmobile: r7s72100: update defconfig for I2C usage

Select the correct I2C driver and activate EEPROM support to have a
slave device for testing. Also activate i2c-dev, so i2c-tools will work.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>