driver: net: ldpaa: Fix Rx buffer alignment

MC 0.7.1.2 enforces limitation i.e.: "Packets may be corrupted
in several combinations of buffer size and frame offsets.
Workaround: Use buffers that are of size that is a multiple of 256, and
frame offset that is a multiple of 256"

Updating the DPNI Eth driver to comply with the restriction.

Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/net/ldpaa_eth/ldpaa_eth.h b/drivers/net/ldpaa_eth/ldpaa_eth.h
index b86a695..af41b27 100644
--- a/drivers/net/ldpaa_eth/ldpaa_eth.h
+++ b/drivers/net/ldpaa_eth/ldpaa_eth.h
@@ -28,10 +28,10 @@
 #define LDPAA_ETH_REFILL_THRESH		(LDPAA_ETH_NUM_BUFS/2)
 #define LDPAA_ETH_RX_BUFFER_SIZE	2048
 
-/* Hardware requires alignment for ingress/egress buffer addresses
- * and ingress buffer lengths.
+/* Hardware requires alignment for buffer address and length: 256-byte
+ * for ingress, 64-byte for egress. Using 256 for both.
  */
-#define LDPAA_ETH_BUF_ALIGN		64
+#define LDPAA_ETH_BUF_ALIGN		256
 
 /* So far we're only accomodating a skb backpointer in the frame's
  * software annotation, but the hardware options are either 0 or 64.