net: Add includes masked by netdevice.h including uapi/bpf.h

Add missing includes unmasked by the subsequent change.

Mostly network drivers missing an include for XDP_PACKET_HEADROOM.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230012742.770642-2-kuba@kernel.org
diff --git a/kernel/bpf/net_namespace.c b/kernel/bpf/net_namespace.c
index 542f275..868cc2c 100644
--- a/kernel/bpf/net_namespace.c
+++ b/kernel/bpf/net_namespace.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/bpf.h>
+#include <linux/bpf-netns.h>
 #include <linux/filter.h>
 #include <net/net_namespace.h>