This patch adds support for mqprio min_rate limiters.

A2 HW supports Weighted Strict Priority (WSP) arbitration for Tx Descriptor
Queue scheduling among TCs, which can be used for min_rate shaping.
Signed-off-by: NMark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: NIgor Russkikh <irusskikh@marvell.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>