clk: x86: lpss-atom: Drop unneeded 'extern' in the header

'extern' for the functions is not needed, drop it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231208165238.3309058-1-andriy.shevchenko@linux.intel.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>