arm: multi_v7_defconfig: enable the Amlogic Meson I2C driver

Some boards come with a PMIC (system power controller, for example Ricoh
RN5T618) which is connected through I2C.
Enable the Meson I2C driver so the devices on the I2C bus can be
registered during boot.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>