Make DNS request for plat prefix detection network specific.

When plat prefix detection is done on a non-default network it
must use the network specific version of getaddrinfo() so the
plat prefix corresponds to the particular network.  The network
is specified to clatd via a NetID command line argument.

Change-Id: I77a47b24e68c7786f790974f05787a40a4934af5
6 files changed