And use this to look for libusb.
If it's there then libdivecomputer likely was linked against it. If it isn't
then we don't need it, either.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The pkg_config_library macro is a helper macro and was generating noise
on the main CMakeLists.txt file, so I moved it to another file.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>