feat(fwu): avoid booting with an alternate boot source

All firmware banks should be part of the same non-volatile storage
as per PSA FWU specification, hence avoid checking for any alternate
boot source when PSA FWU is enabled.

Change-Id: I5b016e59e87f1cbfc73f4cd29fce6017c24f88b3
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/common/bl_common.c b/common/bl_common.c
index f17afcb..a7e2816 100644
--- a/common/bl_common.c
+++ b/common/bl_common.c
@@ -239,9 +239,18 @@
 {
 	int err;
 
+/*
+ * All firmware banks should be part of the same non-volatile storage as per
+ * PSA FWU specification, hence don't check for any alternate boot source
+ * when PSA FWU is enabled.
+ */
+#if PSA_FWU_SUPPORT
+	err = load_auth_image_internal(image_id, image_data);
+#else
 	do {
 		err = load_auth_image_internal(image_id, image_data);
 	} while ((err != 0) && (plat_try_next_boot_source() != 0));
+#endif /* PSA_FWU_SUPPORT */
 
 	return err;
 }