x86, intel_txt: clean up the impact on generic code, unbreak non-x86

Move tboot.h from asm to linux to fix the build errors of intel_txt
patch on non-X86 platforms. Remove the tboot code from generic code
init/main.c and kernel/cpu.c.

Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

drivers/acpi/acpica/hwsleep.c

@@ -45,7 +45,7 @@
 #include <acpi/acpi.h>
 #include "accommon.h"
 #include "actables.h"
-#include <asm/tboot.h>
+#include <linux/tboot.h>
 
 #define _COMPONENT          ACPI_HARDWARE
 ACPI_MODULE_NAME("hwsleep")