ncsi: move ncsi operations to Interface class

The existing NCSI operations are quite Interface-specific (ie., rely on
netlink-specific constructs), so move these to methods on the Interface
class.

We'll add alternative implementations in a future change.

Change-Id: I3ea5fcd64969a2c164503057e35881010ad141a0
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
3 files changed