samples/bpf: Remove the xdp1 and xdp2 utilities

samples/bpf: Remove the xdp1 and xdp2 utilities

The functionality of these utilities have been incorporated into the
xdp-bench utility in xdp-tools.

Equivalent functionality is:

xdp1 eth0
  --> xdp-bench drop -p parse-ip -l load-bytes eth0

xdp2 eth0
  --> xdp-bench drop -p swap-macs eth0

Note that there's a slight difference in behaviour of those examples: the
swap-macs operation of xdp-bench doesn't use the bpf_xdp_load_bytes()
helper to load the packet data, whereas the xdp2 utility did so
unconditionally. For the parse-ip action the use of bpf_xdp_load_bytes()
can be selected by the '-l load-bytes' switch, with the difference that the
xdp-bench utility will perform two separate calls to the helper, one to
load the ethernet header and another to load the IP header; where the xdp1
utility only performed one call always loading 60 bytes of data.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-5-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>