DPE: Fix all test failures

- For reg test, increase number of layers to 6.
- Separate certificate IDs for all the tests where undestroyable
  contexts are created.
- For now, until allocated buffer sizes are passed to the service, return valid
  context handle if DPE service has successfully derived the context.

Signed-off-by: Maulik Patel <maulik.patel@arm.com>
Change-Id: I5766b0df21d79dff569789aedee94bd50c2b9d9a
diff --git a/partitions/dice_protection_environment/dpe_context_mngr.h b/partitions/dice_protection_environment/dpe_context_mngr.h
index dbbc23d..0a35b7c 100644
--- a/partitions/dice_protection_environment/dpe_context_mngr.h
+++ b/partitions/dice_protection_environment/dpe_context_mngr.h
@@ -29,9 +29,13 @@
 
 /* Below configuration defines are platform dependent */
 #define MAX_NUM_OF_COMPONENTS 20
-#define MAX_NUM_OF_LAYERS 4
 #define DPE_PLATFORM_LAYER_IDX 1
 #define DPE_SECURE_WORLD_AND_HYPERVISOR_LAYER_IDX 2
+#ifdef DPE_TEST_MODE
+#define MAX_NUM_OF_LAYERS 6
+#else
+#define MAX_NUM_OF_LAYERS 4
+#endif /* DPE_TEST_MODE */
 
 /* Below threshold defines the threshold below which a context cannot be destroyed */
 #define DPE_DESTROY_CONTEXT_THRESHOLD_LAYER_IDX DPE_SECURE_WORLD_AND_HYPERVISOR_LAYER_IDX