MLK-21076-3 pinctrl: imx7d: Fix build warning when CONFIG_PM_SLEEP=n

MLK-21076-3 pinctrl: imx7d: Fix build warning when CONFIG_PM_SLEEP=n

Fix below build warning when CONFIG_PM_SLEEP=n:

drivers/pinctrl/freescale/pinctrl-imx7d.c:400:12: warning:
'imx7d_pinctrl_resume' defined but not used [-Wunused-function]
 static int imx7d_pinctrl_resume(struct device *dev)
            ^~~~~~~~~~~~~~~~~~~~
drivers/pinctrl/freescale/pinctrl-imx7d.c:394:12: warning:
 'imx7d_pinctrl_suspend' defined but not used [-Wunused-function]

 static int imx7d_pinctrl_suspend(struct device *dev)
            ^~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Jacky Bai <ping.bai@nxp.com>
(cherry picked from commit 219d360b02f74e210c8382de5c8061d660b14241)