ACPI: x86: Move acpi_cmos_rtc to x86 folder

acpi_cmos_rtc is built solely for x86, move it to the respective folder.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>