Support multiple physical cards

Currently, `sfboot_global` just runs sfboot against 1st network interface found to read its state. This leads to wrong results when multiple cards are installed.

Ideally, `sfboot_global` should accept interface name also.. or maybe we should get rid of it and use per-interface type only for everything. It might try to apply "global" changes to every interface though.. not sure how bad this is.

To find adapters installed one can use `sfkey --inventory --all` e.g.

Start by tracing how sfboot_global invokes sfboot and compare it with the per-interface type behavior. Use `sfkey --inventory --all` to identify multiple adapters, then determine whether an interface name should be accepted or global changes should apply to each interface. Done means the chosen behavior handles multiple physical cards without using only the first detected interface.

Written by the indexing model from the issue text.