bpf: allow eBPF programs to use maps

expose bpf_map_lookup_elem(), bpf_map_update_elem(), bpf_map_delete_elem()
map accessors to eBPF programs

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/linux/bpf.h
Simple merge

diff --cc include/uapi/linux/bpf.h
Simple merge

diff --cc kernel/bpf/Makefile
Simple merge

diff --cc kernel/bpf/helpers.c
Simple merge