A missing include causes the following compilation errors:
error: use of undeclared identifier 'AF_INET'
error: use of undeclared identifier 'AF_INET6'
Fixes: ef6e38550f07 ("app/testpmd: add items ipv4/ipv6 to flow command")
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>