Update to v4.20.1 kernel headers.

This includes one manual change:

In the file bionic/libc/kernel/uapi/linux/in.h, the macro IN_BADCLASS
was not definied correctly. Change the macro from:

  #define IN_BADCLASS(a) ((((long int) (a)) == 0xffffffff)

to:

  #define IN_BADCLASS(a) (((long int) (a)) == (long int)0xffffffff)

This change is being pushed to the upstream kernels.

Test: Builds and boots.
Change-Id: Ia304773a9dc6789b34d9769d73742384d6afb571
Merged-In: Ia304773a9dc6789b34d9769d73742384d6afb571
(cherry picked from commit 967fb01cce73591281e7804e2c0fa9f83b618f5b)
diff --git a/libc/kernel/uapi/linux/udmabuf.h b/libc/kernel/uapi/linux/udmabuf.h
new file mode 100644
index 0000000..70cf49f
--- /dev/null
+++ b/libc/kernel/uapi/linux/udmabuf.h
@@ -0,0 +1,43 @@
+/****************************************************************************
+ ****************************************************************************
+ ***
+ ***   This header was automatically generated from a Linux kernel header
+ ***   of the same name, to make information necessary for userspace to
+ ***   call into the kernel available to libc.  It contains only constants,
+ ***   structures, and macros generated from the original header, and thus,
+ ***   contains no copyrightable information.
+ ***
+ ***   To edit the content of this header, modify the corresponding
+ ***   source file (e.g. under external/kernel-headers/original/) then
+ ***   run bionic/libc/kernel/tools/update_all.py
+ ***
+ ***   Any manual change here will be lost the next time this script will
+ ***   be run. You've been warned!
+ ***
+ ****************************************************************************
+ ****************************************************************************/
+#ifndef _UAPI_LINUX_UDMABUF_H
+#define _UAPI_LINUX_UDMABUF_H
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#define UDMABUF_FLAGS_CLOEXEC 0x01
+struct udmabuf_create {
+  __u32 memfd;
+  __u32 flags;
+  __u64 offset;
+  __u64 size;
+};
+struct udmabuf_create_item {
+  __u32 memfd;
+  __u32 __pad;
+  __u64 offset;
+  __u64 size;
+};
+struct udmabuf_create_list {
+  __u32 flags;
+  __u32 count;
+  struct udmabuf_create_item list[];
+};
+#define UDMABUF_CREATE _IOW('u', 0x42, struct udmabuf_create)
+#define UDMABUF_CREATE_LIST _IOW('u', 0x43, struct udmabuf_create_list)
+#endif