eth: fbnic: add missing SPDX headers

Paolo noticed that we are missing SPDX headers, add them.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20241115015344.757567-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c

@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
 #include <linux/ethtool.h>
 #include <linux/netdevice.h>
 #include <linux/pci.h>

drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.c

@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
 #include "fbnic.h"
 
 u64 fbnic_stat_rd64(struct fbnic_dev *fbd, u32 reg, u32 offset)

drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.h

@@ -1,3 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
 #include <linux/ethtool.h>
 
 #include "fbnic_csr.h"