This commits adds GPIO driver for LiteX SoC builder.
Due to the fact that GPIO in LiteX is unidirectional and can be
configured with different pins amount per port, additional entries
were added to the dts file.
Signed-off-by: Robert Winkler <rwinkler@internships.antmicro.com>
Signed-off-by: Mateusz Holenko <mholenko@antmicro.com>
Signed-off-by: Piotr Zierhoffer <pzierhoffer@antmicro.com>