Some of recipes produce errors if the distro has enabled usage of
security_flags.inc file. Fix those errors (and QA warnings) by providing
an additional include file that is require'd from conf/layer.conf.

Signed-off-by: Dmitry Eremin-Solenikov <dmitry_eremin@mentor.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>