configure.ac: place udev files into $prefix/udev
configure.ac: place udev files into $prefix/udev

$libdir is /usr/lib64 on some distros

Fixes #93

Signed-off-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>

cvuchener/libratbag,whot/libratbag,whot/libratbag,libratbag/libratbag,cvuchener/libratbag,whot/libratbag,libratbag/libratbag,libratbag/libratbag,cvuchener/libratbag