arm/hafnium: add hafnium to qemuarm64-secureboot target

Signed-off-by: Csaba Szilágyi <csaba.szilagyi@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

ci/qemuarm64-secureboot.yml

@@ -9,6 +9,7 @@ machine: qemuarm64-secureboot
 
 target:
   - core-image-base
+  - hafnium
 
 local_conf_header:
   optee: |