tests: Add a socket timeout

tests: Add a socket timeout

On FreeBSD a races seems to occur between the states socket connecting
and VPP accepting the connection and calling getpeername. The recv_fd
call here will fail with no fds before the VPP process has time to
handle the connection.

Introducing a socket timeout removes this failure on FreeBSD and allows
the test suite to run. Add a timeout on all platforms to try to avoid
this race everywhere.

Type: improvement
Change-Id: I96f77f924a9491222bc213b534cb17001d081f3f
Signed-off-by: Tom Jones <thj@freebsd.org>