common/cnxk: fix flow deletion

common/cnxk: fix flow deletion

When a flow is deleted, the counters are deleted without
being cleared first. This results in counter values being
retained and shown in flows created later. Hence, counter
is cleared before being deleted.

Updated driver to clear and delete counters upon flow deletion.

Fixes: a07f7ced436d ("common/cnxk: add NPC init and fini")
Cc: stable@dpdk.org
Signed-off-by: Satheesh Paul <psatheesh@marvell.com>
Reviewed-by: Jerin Jacob <jerinj@marvell.com>