mvneta: MVNETA_SKB_HEADROOM set last 3 bits to zero

For XDP the MVNETA_SKB_HEADROOM is used as an offset for
the received data.
The MVNETA manual states that the last 3 bits assumed to be 0.

This is currently the case but lets make it explicit in the definition
to prevent future problems.
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvneta.c

@@ -324,7 +324,8 @@
 	      ETH_HLEN + ETH_FCS_LEN,			     \
 	      cache_line_size())
 
-#define MVNETA_SKB_HEADROOM	max(XDP_PACKET_HEADROOM, NET_SKB_PAD)
+/* Driver assumes that the last 3 bits are 0 */
+#define MVNETA_SKB_HEADROOM	(max(XDP_PACKET_HEADROOM, NET_SKB_PAD) & ~0x7)
 #define MVNETA_SKB_PAD	(SKB_DATA_ALIGN(sizeof(struct skb_shared_info) + \
 			 MVNETA_SKB_HEADROOM))
 #define MVNETA_SKB_SIZE(len)	(SKB_DATA_ALIGN(len) + MVNETA_SKB_PAD)