These tests have been developed in the hid-tools[0] tree for a while.
Now that we have  a proper selftests/hid kernel entry and that the tests
are more reliable, it is time to directly include those in the kernel
tree.

I haven't imported all of hid-tools, the python module, but only the
tests related to the kernel. We can rely on pip to fetch the latest
hid-tools release, and then run the tests directly from the tree.

This should now be easier to request tests when something is not behaving
properly in the HID subsystem.

[0] https://gitlab.freedesktop.org/libevdev/hid-tools

Cc: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>