this updates multimedia/libv4l from 1.14.2 to 1.16.1.
patches/patch-lib_libv4lconvert_control_libv4lcontrol_c is restored from
the CVS attic as there is a regression that was already fixed upstream
in previous versions.
No symbol changes in SHARED_LIBS.
Successfully tested on amd64 in combination with baresip (switching to
USB mode 2 in BIOS such that my webcam still works; a known issue
unrelated to libv4l due to unfinished isochronous transfer support in