This patch add support for I2C on the Renesas R-Car.
This I2C hardware block can be found on various Renesas R-Car
SoC series.
It allows to perfom read and write on I2C buses in an
interrupt based way on R-Car Gen3 H3ULCB board.
Signed-off-by: Aymeric Aillet <aymeric.aillet@iot.bzh>