tls: remove useless legacy function

Signed-off-by: Valerio Setti <vsetti@baylibre.com>
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index a90617f..fb053c6 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -3019,24 +3019,24 @@
         psa_status_t status = PSA_ERROR_GENERIC_ERROR;
         psa_key_attributes_t key_attributes;
         mbedtls_ssl_handshake_params *handshake = ssl->handshake;
-        size_t ecdh_bits = 0;
         uint8_t *p = ssl->out_msg + ssl->out_msglen;
         const size_t header_size = 4; // curve_type(1), namedcurve(2),
                                       // data length(1)
         const size_t data_length_size = 1;
+        psa_ecc_family_t ec_psa_family = 0;
+        size_t ec_bits = 0;
 
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform PSA-based ECDH computation." ) );
 
-        /* Convert EC group to PSA key type. */
-        handshake->ecdh_psa_type = mbedtls_psa_parse_tls_ecc_group(
-                    *curr_tls_id, &ecdh_bits );
-
-        if( handshake->ecdh_psa_type == 0 )
+        /* Convert EC's TLS ID to PSA key type. */
+        if( mbedtls_ssl_get_psa_curve_info_from_tls_id( *curr_tls_id,
+                &ec_psa_family, &ec_bits ) == PSA_ERROR_NOT_SUPPORTED )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid ecc group parse." ) );
             return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
         }
-        handshake->ecdh_bits = ecdh_bits;
+        handshake->ecdh_psa_type = PSA_KEY_TYPE_ECC_KEY_PAIR( ec_psa_family );
+        handshake->ecdh_bits = ec_bits;
 
         key_attributes = psa_key_attributes_init();
         psa_set_key_usage_flags( &key_attributes, PSA_KEY_USAGE_DERIVE );