net:enetc: enetc qos using the CBDR dma alloc function

Now we can use the enetc_cbd_alloc_data_mem() to replace complicated DMA
data alloc method and CBDR memory basic seting.

Signed-off-by: Po Liu <po.liu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>