net/ice: support flow priority for DCF switch filter

net/ice: support flow priority for DCF switch filter

Support rte flow priority attribute for DCF switch filter.
When a packet is matched by two rules, the behavior of it
is not defined. This patch supports flow priority to create
different recipes for this situation. Only priority 0 and 1
are supported and higher value denotes higher priority.

for example:
1. flow create 0 priority 0 ingress pattern eth / vlan tci is 2 / vlan
   tci is 2 / end actions vf id 2 / end
2. flow create 0 priority 1 ingress pattern eth / vlan / vlan / ipv4 dst
   is 192.168.0.1 / end actions vf id 1 / end

These two rules can be created at the same time in DCF switch
filter and priority of rule 2 is higher. Packet hits rule 2
when two conditions of rules are satisfied.

Signed-off-by: Yuying Zhang <yuying.zhang@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>