Replace MBEDTLS_ECP_HAVE_SECP521R1 with PSA_WANT_ECC_SECP_R1_521

Signed-off-by: Elena Uziunaite <elena.uziunaite@arm.com>
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 9c56b44..521c703 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -3555,7 +3555,7 @@
 
     MD_OR_USE_PSA_INIT();
 
-#if defined(MBEDTLS_ECP_HAVE_SECP521R1) || defined(PSA_WANT_ECC_SECP_R1_521)
+#if defined(PSA_WANT_ECC_SECP_R1_521)
     TEST_AVAILABLE_ECC(25, MBEDTLS_ECP_DP_SECP521R1, PSA_ECC_FAMILY_SECP_R1, 521);
 #else
     TEST_UNAVAILABLE_ECC(25, MBEDTLS_ECP_DP_SECP521R1, PSA_ECC_FAMILY_SECP_R1, 521);