doc: update bips.md with buried BIP9 deployments
doc: update bips.md with buried BIP9 deployments

Former-commit-id: 6dcf572705afee8566bbd99372b9720bc1152845
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin