app/testpmd: fix help info for interactive commands

app/testpmd: fix help info for interactive commands

Added some missing help info for interactive mode commands

Fixes: 6673fe0ce213 ("app/testpmd: add TM commands to mark packets")
Fixes: c73a9071877a ("app/testpmd: add commands to test new offload API")
Fixes: e977e4199a8d ("app/testpmd: add commands to load/unload BPF filters")
Fixes: c18feafa193c ("app/testpmd: support metadata as flow rule item")
Cc: stable@dpdk.org
Signed-off-by: Agalya Babu RadhaKrishnan <agalyax.babu.radhakrishnan@intel.com>
Reviewed-by: Rami Rosen <ramirose@gmail.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>