Update to v6.3 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-6.3

Test: Bionic unit tests pass.
Change-Id: I5270ef291a77343e47ef3a5fbd02b8cacf218ec5
diff --git a/libc/kernel/uapi/linux/version.h b/libc/kernel/uapi/linux/version.h
index 0d50613..9d48e3d 100644
--- a/libc/kernel/uapi/linux/version.h
+++ b/libc/kernel/uapi/linux/version.h
@@ -16,8 +16,8 @@
  ***
  ****************************************************************************
  ****************************************************************************/
-#define LINUX_VERSION_CODE 393728
+#define LINUX_VERSION_CODE 393984
 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255 : (c)))
 #define LINUX_VERSION_MAJOR 6
-#define LINUX_VERSION_PATCHLEVEL 2
+#define LINUX_VERSION_PATCHLEVEL 3
 #define LINUX_VERSION_SUBLEVEL 0