Revert "Update bionic kernel headers using update_all.py"

This reverts commit 94a85f663694e1869acb1c2e8a3c374a6fa3ab86

There is a smoke test failure for Prime but Crespo/Stingray are fine. Will revert the change for now until further investigation is made.
diff --git a/libc/kernel/arch-arm/asm/arch/serial.h b/libc/kernel/arch-arm/asm/arch/serial.h
index e11c53a..6ab8613 100644
--- a/libc/kernel/arch-arm/asm/arch/serial.h
+++ b/libc/kernel/arch-arm/asm/arch/serial.h
@@ -7,20 +7,15 @@
  ***   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 __ASM_ARCH_SERIAL_H
 #define __ASM_ARCH_SERIAL_H
+
 #define OMAP_MAX_NR_PORTS 3
 #define OMAP1510_BASE_BAUD (12000000/16)
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define OMAP16XX_BASE_BAUD (48000000/16)
+
 #define is_omap_port(p) ({int __ret = 0;   if (p == IO_ADDRESS(OMAP_UART1_BASE) ||   p == IO_ADDRESS(OMAP_UART2_BASE) ||   p == IO_ADDRESS(OMAP_UART3_BASE))   __ret = 1;   __ret;   })
+
 #endif