Change definition of acpi_thread_id to always be a u64. This
simplifies the code, especially any printf output. u64 is
the only common data type for all thread_id types across all
operating systems. We now force the OSL to cast the native
thread_id type to u64 before returning the value to ACPICA
(via acpi_os_get_thread_id).

Signed-off-by: Lin Ming <ming.m.lin@intel.com
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>