[test] Add rom_e2e_sigverify_key_auth

Fixes #14478

Signed-off-by: Alphan Ulusoy <alphan@google.com>
diff --git a/rules/opentitan.bzl b/rules/opentitan.bzl
index b1aba0e..64aa9c6 100644
--- a/rules/opentitan.bzl
+++ b/rules/opentitan.bzl
@@ -45,6 +45,7 @@
 # Default keys used to sign ROM_EXT and BL0 images for testing.
 DEFAULT_SIGNING_KEYS = {
     "test_key_0": "@//sw/device/silicon_creator/rom/keys:test_private_key_0",
+    "unauthorized_0": "@//sw/device/silicon_creator/rom/keys:unauthorized_private_key_0",
 }
 
 def _obj_transform_impl(ctx):