bpf: expose program stats via bpf_prog_info

Return bpf program run_time_ns and run_cnt via bpf_prog_info

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>