gobject-introspection: fix floating dep on python-mako
This was resulting in non-deterministic builds where g-ir-doc-tool may or may
not exist depending on whether python-mako was built previously. Add
a PACKAGECONFIG so the dependency is explicit.
Signed-off-by: Sujith H <sujith.h@gmail.com> Signed-off-by: Christopher Larson <chris_larson@mentor.com> Signed-off-by: Sujith Haridasan <Sujith_Haridasan@mentor.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
