test: minor enhancement for using the new private key format

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/tests/suites/test_suite_pkparse.function b/tests/suites/test_suite_pkparse.function
index a49b6d3..6fa78c1 100644
--- a/tests/suites/test_suite_pkparse.function
+++ b/tests/suites/test_suite_pkparse.function
@@ -117,10 +117,13 @@
     TEST_ASSERT(res == result);
 
     if (res == 0) {
-        const mbedtls_ecp_keypair *eckey;
         TEST_ASSERT(mbedtls_pk_can_do(&ctx, MBEDTLS_PK_ECKEY));
-        eckey = mbedtls_pk_ec_ro(ctx);
+#if defined(MBEDTLS_ECP_C)
+        const mbedtls_ecp_keypair *eckey = mbedtls_pk_ec_ro(ctx);
         TEST_ASSERT(mbedtls_ecp_check_privkey(&eckey->grp, &eckey->d) == 0);
+#else
+        /* PSA keys are already checked on import so nothing to do here. */
+#endif
     }
 
 exit: