pinctrl: baytrail: Add debounce configuration

Make debounce setting and getting functionality available when
configurating a certain pin.

Signed-off-by: Cristina Ciocan <cristina.ciocan@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>