Fix LMOTS signature leak test dependencies

As it requires MBEDTLS_LMS_PRIVATE

Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/tests/suites/test_suite_lmots.function b/tests/suites/test_suite_lmots.function
index 367e55a..d540454 100644
--- a/tests/suites/test_suite_lmots.function
+++ b/tests/suites/test_suite_lmots.function
@@ -211,7 +211,7 @@
 }
 /* END_CASE */
 
-/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS */
+/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_LMS_PRIVATE */
 void lmots_signature_leak_test ( data_t *msg, data_t *key_id, int leaf_id,
                                  data_t *seed )
 {