xlib_libpciaccess: Rename package to libpciaccess

While libpciaccess is part of the X libraries, it does not
depend upon X11 or any other X library.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>