Deprecate function calls for Ethernet filter

[mengxiang0811]

In the latest DPDK, two function calls (i.e., rte_eth_dev_filter_supported() and rte_eth_dev_filter_ctrl()) are being deprecated. In gatekeeper, we use them to add EtherType filters as well as ntuple filters. To fully update to the latest DPDK, we need to deprecate these function calls, and instead we will use the generic filter APIs.

This issue relates to #272

[AltraMayor]

Is it possible to just replace these calls with their corresponding calls in the filter API? Or does it require a rewrite of some part of Gatekeeper?

[mengxiang0811]

We need to use the generic flow API to replace the above functions. I will give an update after reviewing these APIs as it seems not simple replace.

[AltraMayor]

This issue should also remove -Wno-deprecated-declarations from the variable EXTRA_CFLAGS in the `Makefile.