perf bpf: Add linux/socket.h to the headers accessible to bpf proggies

perf bpf: Add linux/socket.h to the headers accessible to bpf proggies

So that we don't have to define sockaddr_storage in the
augmented_syscalls.c bpf example when hooking into syscalls needing it,
idea is to mimic the system headers. Eventually we probably need to have
sys/socket.h, etc.  Start by having at least linux/socket.h.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-yhzarcvsjue8pgpvkjhqgioc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>