ar71xx/ath79: ag71xx: init rings with GFP_KERNEL

Upstream commit	246902bdf562d45ea3475fac64c93048a7a39f01

Which contains following explanation:

--
There is no need to use GFP_ATOMIC here, GFP_KERNEL should be enough.
The 'kcalloc()' just a few lines above, already uses GFP_KERNEL.
--

Looking at the code, all other descriptors also use plain GFP_KERNEL

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>

target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c

@@ -277,7 +277,7 @@ static int ag71xx_rings_init(struct ag71xx *ag)
 		return -ENOMEM;
 
 	tx->descs_cpu = dma_alloc_coherent(&ag->pdev->dev, ring_size * AG71XX_DESC_SIZE,
-					   &tx->descs_dma, GFP_ATOMIC);
+					   &tx->descs_dma, GFP_KERNEL);
 	if (!tx->descs_cpu) {
 		kfree(tx->buf);
 		tx->buf = NULL;