ARM: mvebu: add I2C0 muxing option for Armada 370 SoC

This commit adds a pin-muxing configuration for the I2C0 bus of the
Armada 370, which is used on the Armada 370 DB platform to interface
with the CS42L51 audio codec.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>