Set code owners for src/goto-bmc.

Setting the `CODEOWNERS` file entry for `src/goto-bmc` folder.

Author: Enrico Steffinlongo

CODEOWNERS

@@ -50,6 +50,7 @@
 # These files change frequently and changes are medium-risk
 
 /src/goto-analyzer/ @martin-cs @peterschrammel
+/src/goto-bmc/ @NlightNFotis @thomasspriggs @esteffin @TGWDB @peterschrammel
 /src/goto-harness/ @martin-cs @peterschrammel
 /src/goto-instrument/ @martin-cs @peterschrammel @tautschnig @kroening
 /src/goto-instrument/contracts/ @tautschnig @feliperodri @remi-delmas-3000