ip: add handling for new CAN netlink interface

ip: add handling for new CAN netlink interface

This patch adds handling for new CAN netlink interface introduced in
4.11 kernel:
- IFLA_CAN_TERMINATION,
- IFLA_CAN_TERMINATION_CONST,
- IFLA_CAN_BITRATE_CONST,
- IFLA_CAN_DATA_BITRATE_CONST

Output example:
$ip -d link show can0
6: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT group default qlen 10
    link/can  promiscuity 0
    can state STOPPED (berr-counter tx 0 rx 0) restart-ms 0
          bitrate 80000
             [   20000,    33333,    50000,    80000,    83333,   100000,
                125000,   150000,   175000,   200000,   225000,   250000,
                275000,   300000,   500000,   625000,   800000,  1000000 ]
          termination 0 [ 0, 120 ]
          clock 0numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535

Signed-off-by: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>