gpio: elkhartlake: Introduce Intel Elkhart Lake PSE GPIO

This driver adds support for Intel Elkhart Lake PSE GPIO controller,
using Intel Tangier as a library driver.

Signed-off-by: Pandith N <pandith.n@intel.com>
Co-developed-by: Raag Jadav <raag.jadav@intel.com>
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>