Update to v4.19 kernel headers.

Test: Builds and boots.
Change-Id: I99a9ed79666e143b47f02ca4e59eed94f69b7e4a
(cherry picked from commit a981e2e52e2e95a65fa9c9b6fb16dcb4c83dd576)
diff --git a/libc/kernel/uapi/drm/vc4_drm.h b/libc/kernel/uapi/drm/vc4_drm.h
index 05ed172..29eb872 100644
--- a/libc/kernel/uapi/drm/vc4_drm.h
+++ b/libc/kernel/uapi/drm/vc4_drm.h
@@ -91,6 +91,8 @@
   __u32 flags;
   __u64 seqno;
   __u32 perfmonid;
+  __u32 in_sync;
+  __u32 out_sync;
   __u32 pad2;
 };
 struct drm_vc4_wait_seqno {