libgpiod: add package for library and tools

libgpiod: add package for library and tools

libgpiod is a C library with corresponding tools for interacting
with the linux GPIO character device (gpiod stands for GPIO device).

Since linux 4.8 the GPIO sysfs interface is deprecated. User space should use
the character device instead. This library encapsulates the ioctl calls and
data structures behind a straightforward API.

Import the package from packages feed without the Python3 package, as
ugpiod depends on the library.

Signed-off-by: Petr Štetiar <ynezz@true.cz>