Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/include/net/psample.h b/include/net/psample.h
index 68ae16b..20a1755 100644
--- a/include/net/psample.h
+++ b/include/net/psample.h
@@ -18,6 +18,8 @@ struct psample_group *psample_group_get(struct net *net, u32 group_num);
 void psample_group_take(struct psample_group *group);
 void psample_group_put(struct psample_group *group);
 
+struct sk_buff;
+
 #if IS_ENABLED(CONFIG_PSAMPLE)
 
 void psample_sample_packet(struct psample_group *group, struct sk_buff *skb,