cgroup, bpf: remove unnecessary #include

this #include is unnecessary and brings whole set of
other headers into cgroup-defs.h. Remove it.

Fixes: 30070984 ("cgroup: add support for eBPF programs")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Rami Rosen <roszenrami@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: David S. Miller <davem@davemloft.net>