linux-imx

bpf: sync bpf.h to tools and update bpf_helpers.h

This patch syncs the uapi bpf.h to tools/ and also updates
bpf_herlpers.h in tools/

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>