bpf: Add BPF_MAP_TYPE_LRU_PERCPU_HASH

Provide a LRU version of the existing BPF_MAP_TYPE_PERCPU_HASH

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>