bpf: reduce runtime of test_sockmap tests

bpf: reduce runtime of test_sockmap tests

When test_sockmap was running outside of selftests and was not being
run by build bots it was reasonable to spend significant amount of
time running various tests. The number of tests is high because many
different I/O iterators are run.

However, now that test_sockmap is part of selftests rather than
iterate through all I/O sides only test a minimal set of min/max
values along with a few "normal" I/O ops. Also remove the long
running tests. They can be run from other test frameworks on a regular
cadence.

This significanly reduces runtime of test_sockmap.

Before:

$ time sudo ./test_sockmap  > /dev/null

real    4m47.521s
user    0m0.370s
sys     0m3.131s

After:

$ time sudo ./test_sockmap  > /dev/null

real    0m0.514s
user    0m0.104s
sys     0m0.430s

The CLI is still available for users that want to test the long
running tests that do the larger send/recv tests.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>