Do not fetch submodules recursively
hdlmake master (after 2.1) automatically
detects all git submodules and refuses to work if all the submodules are not fetched
recursively. It is somehow against our (internal) guildelines. We do not use submodules
recursively but rather use flat structure, i.e. if we have a project that uses wr-cores
and general-cores, we declare both as submodules in the ip_cores and do not fetch
submodules inside wr-cores. We had a long discussion about pros and cons of
recursive versus non-recursive and the latter was decided to be the way.