bpf: Sync tools/include/uapi/linux/bpf.h

Commit 47316f4a missed updating tools/.../bpf.h.
Sync it.

Fixes: 47316f4a ("bpf: Support input xdp_md context in BPF_PROG_TEST_RUN")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>