psa_exercise_key: add missing #else for KNOWN_SUPPORTED_BLOCK_CIPHER

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/tests/include/test/psa_exercise_key.h b/tests/include/test/psa_exercise_key.h
index bd523d1..a658d17 100644
--- a/tests/include/test/psa_exercise_key.h
+++ b/tests/include/test/psa_exercise_key.h
@@ -52,6 +52,7 @@
 #define KNOWN_SUPPORTED_BLOCK_CIPHER PSA_KEY_TYPE_ARIA
 #elif defined(PSA_WANT_KEY_TYPE_CAMELLIA)
 #define KNOWN_SUPPORTED_BLOCK_CIPHER PSA_KEY_TYPE_CAMELLIA
+#else
 #undef KNOWN_SUPPORTED_BLOCK_CIPHER
 #endif