Remove the definition of `struct cmdline` from public header.
Deprecation notice:
https://mails.dpdk.org/archives/dev/2020-September/183310.html
Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Acked-by: David Marchand <david.marchand@redhat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Narcisa Vasile <navasile@linux.microsoft.com>