This driver is generic and aims to support all Technologic Systems's
boards embedding FPGA GPIOs with an I2C interface.

This driver supports TS-4900, TS-7970, TS-7990 and TS-4100 series.
Signed-off-by: NLucile Quirion <lucile.quirion@savoirfairelinux.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>