Add interuptible export public-key testing to invalid key tests

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>
diff --git a/tf-psa-crypto/tests/suites/test_suite_psa_crypto.function b/tf-psa-crypto/tests/suites/test_suite_psa_crypto.function
index 00b935b..c72511b 100644
--- a/tf-psa-crypto/tests/suites/test_suite_psa_crypto.function
+++ b/tf-psa-crypto/tests/suites/test_suite_psa_crypto.function
@@ -222,6 +222,9 @@
 {
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     mbedtls_svc_key_id_t key_id = mbedtls_svc_key_id_make(1, 0x6964);
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    psa_export_public_key_iop_t export_key_iop = PSA_EXPORT_PUBLIC_KEY_IOP_INIT;
+#endif
     uint8_t buffer[1];
     size_t length;
     int ok = 0;
@@ -248,6 +251,11 @@
                                      buffer, sizeof(buffer), &length),
                PSA_ERROR_INVALID_HANDLE);
 
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    TEST_EQUAL(psa_export_public_key_iop_setup(&export_key_iop, key),
+               PSA_ERROR_INVALID_HANDLE);
+#endif
+
     ok = 1;
 
 exit: