spd: trusty: trusty_setup should bail on unknown image

When an unknown Trusty image is found, there's no point of still trying
to register the BL32 init handler. Instead, we just should bail out of
the trusty_setup() and allow the system to continue to boot.

Signed-off-by: David Lin <dtwlin@google.com>
diff --git a/services/spd/trusty/trusty.c b/services/spd/trusty/trusty.c
index c9d73f0..9741916 100644
--- a/services/spd/trusty/trusty.c
+++ b/services/spd/trusty/trusty.c
@@ -416,7 +416,8 @@
 	} else if (instr >> 8 == 0xd53810U || instr >> 16 == 0x9400U) {
 		INFO("trusty: Found 64 bit image\n");
 	} else {
-		NOTICE("trusty: Found unknown image, 0x%x\n", instr);
+		ERROR("trusty: Found unknown image, 0x%x\n", instr);
+		return -1;
 	}
 
 	SET_PARAM_HEAD(ep_info, PARAM_EP, VERSION_1, SECURE | EP_ST_ENABLE);