gl.pc should be packaged in libgl-dev not the mesa-dev package
Fixes [YOCTO #2059]
(From OE-Core rev: d9d4fe9885e398df2062b3f2aed3fc274c656736)
Signed-off-by: Joshua Lock <josh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>