CI: Add zephyr testimage

Add the ability to run testimage against zephyr machines.
Unfortunately, this exposes a bug in meta-zephyr with TESTIMAGE_AUTO not
working correctly.  So, work around this until it can be fixed upstream.
Also, qemu-cortex-a53 does not successfully pass any of the tests it
successfully builds.  So, don't run testimage until that can be
addressed.

Signed-off-by: Jon Mason <jon.mason@arm.com>

ci/microbit-v1.yml

@@ -4,7 +4,13 @@ header:
     - base.yml
     - meta-zephyr.yml
 
+local_conf_header:
+  nonbuilding_tests: |
+    ZEPHYRTESTS:remove = "common"
+  failing_tests: |
+    ZEPHYRTESTS:remove = "context early_sleep sleep"
+
 machine: microbit-v1
 
 target:
-  - zephyr-philosophers
+  - zephyr-kernel-test-all