pinctrl: samsung: Document suspend and resume members

Add missing documentation for suspend and resume members of struct
samsung_pin_ctrl and samsung_pinctrl_drv_data.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Sylwester Nawrocki <snawrocki@kernel.org>
Acked-by: Tomasz Figa <tomasz.figa@gmail.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

drivers/pinctrl/samsung/pinctrl-samsung.h

@@ -223,6 +223,10 @@ struct samsung_retention_data {
  *	interrupts for the controller.
  * @eint_wkup_init: platform specific callback to setup the external wakeup
  *	interrupts for the controller.
+ * @suspend: platform specific suspend callback, executed during pin controller
+ *	device suspend, see samsung_pinctrl_suspend()
+ * @resume: platform specific resume callback, executed during pin controller
+ *	device suspend, see samsung_pinctrl_resume()
  */
 struct samsung_pin_ctrl {
 	const struct samsung_pin_bank_data *pin_banks;
@@ -255,6 +259,10 @@ struct samsung_pin_ctrl {
  * @pin_base: starting system wide pin number.
  * @nr_pins: number of pins supported by the controller.
  * @retention_ctrl: retention control runtime data.
+ * @suspend: platform specific suspend callback, executed during pin controller
+ *	device suspend, see samsung_pinctrl_suspend()
+ * @resume: platform specific resume callback, executed during pin controller
+ *	device suspend, see samsung_pinctrl_resume()
  */
 struct samsung_pinctrl_drv_data {
 	struct list_head		node;