Revert^2 "Use unicast instead of broadcast as ethernet destination in `test_apf_drop_ethercat`"

This reverts commit c3eccf9ef4c2ba311e37f077fb56a6258b3d3b86.

Reason for revert: As we discussed, it might be valid for the chipset to drop BC (non-ARP, non-IPv4) packets in the hardware instead of the firmware. To ensure this test doesn't fail on those chipsets, using unicast packets for testing seems more suitable.

Change-Id: I89debf79965cf3ea62484c443e952bd137818efc
1 file changed