move bpf prog specific header file into bpf_progs directory

as it simply isn't a part of libnetdbpf

Test: builds
Bug: 141532657
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I0903aa069e713d0dccf71f67e8e0359622a4e9bd
2 files changed