To avoid memory waste, can add support for using an independent iob buffer
The IP protocol often configures CONFIG_IOB_BUFSIZE to be relatively large,
such as 512, for higher throughput. However, the buffer required by CAN is
fixed at a length of 16 or 64. If the system's IOB is directly used,
a lot of memory will be wasted.
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>