net: macb: add XDP support for gem

Introduce basic XDP support for macb/gem with the XDP_TX, XDP_PASS,
XDP_DROP, XDP_REDIRECT verdict support.

Signed-off-by: Paolo Valerio <pvalerio@redhat.com>

Author: vlrpl

drivers/net/ethernet/cadence/macb.h

@@ -15,6 +15,7 @@
 #include <linux/phy/phy.h>
 #include <linux/workqueue.h>
 #include <net/page_pool/helpers.h>
+#include <net/xdp.h>
 
 #if defined(CONFIG_ARCH_DMA_ADDR_T_64BIT) || defined(CONFIG_MACB_USE_HWSTAMP)
 #define MACB_EXT_DESC
@@ -1317,6 +1318,7 @@ struct macb_queue {
 	struct queue_stats stats;
 	struct page_pool	*page_pool;
 	struct sk_buff		*skb;
+	struct xdp_rxq_info	xdp_rxq;
 };
 
 struct ethtool_rx_fs_item {
@@ -1432,6 +1434,7 @@ struct macb {
 
 	struct macb_pm_data pm_data;
 	const struct macb_usrio_config *usrio;
+	struct bpf_prog	__rcu *prog;
 };
 
 #ifdef CONFIG_MACB_USE_HWSTAMP