mac80211: backport napi_build_skb for 5.10

It is needed for an upcoming mt76 update

Signed-off-by: Felix Fietkau <[email protected]>

package/kernel/mac80211/patches/build/110-backport_napi_build_skb.patch

@@ -0,0 +1,11 @@
+--- a/backport-include/linux/skbuff.h
++++ b/backport-include/linux/skbuff.h
+@@ -140,4 +140,8 @@ static inline u64 skb_get_kcov_handle(st
+ }
+ #endif
+ 
++#if LINUX_VERSION_IS_LESS(5,11,0)
++#define napi_build_skb build_skb
++#endif
++
+ #endif /* __BACKPORT_SKBUFF_H */