gitlab-ci: add meta-hardening build image

Signed-off-by: Armin Kuster <akuster808@gmail.com>

kas/kas-security-base.yml

@@ -10,6 +10,7 @@ repos:
       meta-tpm:
       meta-integrity:
       meta-security-compliance:
+      meta-hardening:
 
   poky:
     url: https://git.yoctoproject.org/git/poky

kas/qemux86-harden.yml

@@ -0,0 +1,10 @@
+header:
+  version: 8
+  includes:
+    - kas-security-base.yml
+
+local_conf_header:
+  meta-security: |
+    DISTRO = "harden"
+
+machine: qemux86