BoringCrypto: RDSEED as entropy source


We are using BoringCrypto in our products and we would like to use RDSEED as entropy source for the CTR DRBG In boringcrypto. From the doc and code of boring crypto, it seems only RDRAND is available. Is there a way RDSEED can be made as entropy source in boringcrypto by enabling some flag or any other means? Appreciate your assistance. Thanks!