libgpiod: bump version to v1.0.1

libgpiod: bump version to v1.0.1

This is a bugfix release. It contains the following changes since v1.0:

- include Doxyfile in the release tarball
- fix the implicit-fallthrough warnings
- make tests work together with gpio-mockup post v4.16 linux kernel
- use reference counting for line file descriptors to avoid calling
  close() on the same descriptors multiple times

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>