Add support to set rx buf len via ethtool -G parameter and get
rx buf len via ethtool -g parameter.
Signed-off-by: NHao Chen <chenhao288@hisilicon.com>
Signed-off-by: NGuangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>