Update description in pkg-config file to more generic one
Update description in pkg-config file to more generic one

Tatsh/libimobiledevice,upbit/libimobiledevice,patweb/libimobiledevice,libimobiledevice/libimobiledevice,Tatsh/libimobiledevice,kalev/libimobiledevice,kalev/libimobiledevice,upbit/libimobiledevice,upbit/libimobiledevice,kalev/libimobiledevice,libimobiledevice-win32/libimobiledevice,patweb/libimobiledevice,libimobiledevice-win32/libimobiledevice,libimobiledevice/libimobiledevice,patweb/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,libimobiledevice-win32/libimobiledevice,Tatsh/libimobiledevice