atl1c: Fix misuse of netdev_alloc_skb in refilling rx ring

atl1c: Fix misuse of netdev_alloc_skb in refilling rx ring

atl1c uses netdev_alloc_skb to refill its rx dma ring, but that call makes no
guarantees about the suitability of the memory for use in DMA.  As a result
we've gotten reports of atl1c drivers occasionally hanging and needing to be
reset:
https://bugzilla.kernel.org/show_bug.cgi?id=54021

Fix this by modifying the call to use the internal version __netdev_alloc_skb,
where you can set the gfp_mask explicitly to include GFP_DMA.

Tested by two reporters in the above bug, who have the hardware to validate it.
Both report immediate cessation of the problem with this patch

Signed-off-by: Neil Horman <[email protected]>
CC: Jay Cliburn <[email protected]>
CC: "David S. Miller" <[email protected]>
CC: [email protected]
Tested-by: Luis Henriques <[email protected]>
Tested-by: Vincent Alquier <[email protected]>
Signed-off-by: David S. Miller <[email protected]>