pinctrl: cherryview: Add chv_gpio_clear_triggering() helper function

This is a preparation patch for clearing the interrupt trigger from
chv_gpio_disable_free().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>