ncsi: log interface types using to_string

Add a to_string() method for Interfaces, to handle printing via lg2.

Since we're printing the interface object, don't specify _INDEX on the
metadata, this may not always be an index.

Also, interface indices are typically referred to as decimal. Use
decimal instead of a lg2::hex conversion.

Change-Id: I90b5fbac52adde3bbc3f2699087373ed96361083
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
2 files changed