net: mvpp2: Add xdp tx return bulking support

Convert mvpp2 driver to xdp_return_frame_bulk APIs.

XDP_REDIRECT (upstream codepath): 1.79Mpps
XDP_REDIRECT (upstream codepath + bulking APIs): 1.93Mpps

Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Matteo Croce <mcroce@microsoft.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/0b38c295e58e8ce251ef6b4e2187a2f457f9f7a3.1605267335.git.lorenzo@kernel.org