net/softnic: support flow flush
net/softnic: support flow flush

Add rte flow flush api for flushing
all the flows of the port.

Signed-off-by: Reshma Pattan <4d9eb35579760ed1c2db754a6b402039c9c8a1cb@intel.com>
Acked-by: Cristian Dumitrescu <25468b8a3698eeb3c368247f8635924bb4a1ce2c@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk