sstate: Add extra intercept functions SSTATEPOSTCREATEFUNCS
In some cases we do either need to add extra sstate manipulation
functions, or change the existing modification functions. This patch
parametrizes it to SSTATEPOSTCREATEFUNCS after sstate_create_package
Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com> Signed-off-by: Saul Wold <sgw@linux.intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
