CI: add genericarm64

Add the new genericarm64 in meta-yocto-bsp to the CI.

This new BSP is heavily based on the meta-arm generic-arm64 machine, but
with an all-new fragmented kernel configuration.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

.gitlab-ci.yml

@@ -161,6 +161,15 @@ arm-systemready-ir-acs:
 fvps:
   extends: .build
 
+genericarm64:
+  extends: .build
+  parallel:
+    matrix:
+      - TOOLCHAINS: [gcc, clang]
+        TESTING: testimage
+      - KERNEL: linux-yocto-dev
+        TESTING: testimage
+
 generic-arm64:
   extends: .build