net: stmmac: selftests: Add selftest for L3/L4 Filters

Adds the selftests for L3 and L4 filters with DA/SA/DP/SP support.

Changes from v1:
	- Reduce stack usage (kbuild test robot)

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>