Update to v5.5 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.5

Test: Boots on walleye.
Test: Ran bionic-unit-tests on walleye.
Test: Boots on cuttlefish.
Test: Ran bionic-unit-tests on cuttlefish.
Change-Id: I57387d3c31e0ba5ad125ffe291cecf365c7b374e
diff --git a/libc/kernel/uapi/linux/gen_stats.h b/libc/kernel/uapi/linux/gen_stats.h
index 0b6c228..2df6616 100644
--- a/libc/kernel/uapi/linux/gen_stats.h
+++ b/libc/kernel/uapi/linux/gen_stats.h
@@ -28,6 +28,7 @@
   TCA_STATS_RATE_EST64,
   TCA_STATS_PAD,
   TCA_STATS_BASIC_HW,
+  TCA_STATS_PKT64,
   __TCA_STATS_MAX,
 };
 #define TCA_STATS_MAX (__TCA_STATS_MAX - 1)
@@ -35,10 +36,6 @@
   __u64 bytes;
   __u32 packets;
 };
-struct gnet_stats_basic_packed {
-  __u64 bytes;
-  __u32 packets;
-} __attribute__((packed));
 struct gnet_stats_rate_est {
   __u32 bps;
   __u32 pps;