ethdev: add fuzzy match in flow API

ethdev: add fuzzy match in flow API

Add new meta pattern item RTE_FLOW_TYPE_ITEM_FUZZY in flow API.

This is for device that support fuzzy match option.
Usually a fuzzy match is fast but the cost is accuracy.
i.e. Signature Match only match pattern's hash value, but it is
possible that two different patterns have the same hash value.

Matching accuracy level can be configured by subfield threshold.
Driver can divide the range of threshold and map to different
accuracy levels that device support.

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