platform/x86: intel_speed_select_if: Move to intel sub-directory

platform/x86: intel_speed_select_if: Move to intel sub-directory

Move Intel Speed Select interface driver to intel sub-directory to improve
readability and rename it from intel_speed_select_if to speed_select_if.

Signed-off-by: Kate Hsuan <hpa@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210820110458.73018-14-andriy.shevchenko@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>