PPC: bpf_jit_comp: add SKF_AD_HATYPE instruction

Add BPF extension SKF_AD_HATYPE to ppc JIT to check
the hw type of the interface

Before:
[   57.723666] test_bpf: #20 LD_HATYPE
[   57.723675] BPF filter opcode 0020 (@0) unsupported
[   57.724168] 48 48 PASS

After:
[  103.053184] test_bpf: #20 LD_HATYPE 7 6 PASS

CC: Alexei Starovoitov<alexei.starovoitov@gmail.com>
CC: Daniel Borkmann<dborkman@redhat.com>
CC: Philippe Bergheaud<felix@linux.vnet.ibm.com>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>

v2: address Alexei's comments
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>