contrib: Support alternative orgs in `get_remote`
contrib: Support alternative orgs in `get_remote`

This commit adds a optional positional argument to `get_remote` to allow
obtaining the remote of Cilium forks in other organizations than the
default `cilium` one.

Signed-off-by: Sebastian Wicki <db043b2055cb3a47b2eb0b5aebf4e114a8c24a5a@isovalent.com>

cilium/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium