veth: sctp: add NETIF_F_SCTP_CRC to device features

Commit b17c7069

 ("loopback: sctp: add NETIF_F_SCTP_CSUM to device
features") added NETIF_F_SCTP_CRC to device features for lo device to
improve the performance of sctp over lo.

This patch is to add NETIF_F_SCTP_CRC to device features for veth to
improve the performance of sctp over veth.

Before this patch:
  ip netns exec cs_client netperf -H 10.167.12.2 -t SCTP_STREAM -- -m 10K
  Recv   Send    Send
  Socket Socket  Message  Elapsed
  Size   Size    Size     Time     Throughput
  bytes  bytes   bytes    secs.    10^6bits/sec

  212992 212992  10240    10.00    1117.16

After this patch:
  ip netns exec cs_client netperf -H 10.167.12.2 -t SCTP_STREAM -- -m 10K
  Recv   Send    Send
  Socket Socket  Message  Elapsed
  Size   Size    Size     Time     Throughput
  bytes  bytes   bytes    secs.    10^6bits/sec

  212992 212992  10240    10.20    1415.22

Tested-by: Li Shuang <tjlishuang@yeah.net>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>