pwm: tiecap: add CONFIG_PM_SLEEP to ecap_pwm_{save,restore}_context()

ecap_pwm_save_context() and ecap_pwm_restore_context() are only used
when CONFIG_PM_SLEEP is selected.

drivers/pwm/pwm-tiecap.c:293:13: warning: 'ecap_pwm_save_context' defined but not used [-Wunused-function]
drivers/pwm/pwm-tiecap.c:302:13: warning: 'ecap_pwm_restore_context' defined but not used [-Wunused-function]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-tiecap.c

@@ -290,6 +290,7 @@ static int ecap_pwm_remove(struct platform_device *pdev)
 	return pwmchip_remove(&pc->chip);
 }
 
+#ifdef CONFIG_PM_SLEEP
 static void ecap_pwm_save_context(struct ecap_pwm_chip *pc)
 {
 	pm_runtime_get_sync(pc->chip.dev);
@@ -306,7 +307,6 @@ static void ecap_pwm_restore_context(struct ecap_pwm_chip *pc)
 	writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2);
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int ecap_pwm_suspend(struct device *dev)
 {
 	struct ecap_pwm_chip *pc = dev_get_drvdata(dev);