x86, realmode: Move reboot_32.S to unified realmode code

Migrated reboot_32.S from x86_trampoline to the real-mode
blob.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-5-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/realmode/rm/header.S

@@ -13,4 +13,7 @@ ENTRY(real_mode_header)
 		.long	pa_text_start
 		.long	pa_ro_end
 		.long	pa_end
+#ifdef CONFIG_X86_32
+		.long	pa_machine_real_restart_asm
+#endif
 END(real_mode_header)