When doing builds using sstate cache, there was no way to run
the equivalent of a pkg_postinst function. This is needed by
the SGML-related documentation recipes to properly update the
catalog files when new DTDs and stylesheets are installed.
SSTATEPOSTINSTFUNCS is a new variable you can set to function(s)
in your recipe to run after install is completed from sstate.
Thanks to Richard Purdie for suggesting this solution.
Signed-off-by: Scott Garman <scott.a.garman@intel.com>
