net: stmmac: rearrange RX and TX desc init into per-queue basis

Below functions are made to be per-queue in preparation of XDP ZC:

 __init_dma_rx_desc_rings(struct stmmac_priv *priv, u32 queue, gfp_t flags)
 __init_dma_tx_desc_rings(struct stmmac_priv *priv, u32 queue)

The original functions below are stay maintained for all queue usage:

 init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 init_dma_tx_desc_rings(struct net_device *dev)

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>