mfd: as3722: Mark PM functions as __maybe_unused

The newly introduced as3722_i2c_suspend/resume functions are built
unconditionally, but only used when power management is enabled,
so we get a warning otherwise:

drivers/mfd/as3722.c:427:12: warning: 'as3722_i2c_suspend' defined but not used [-Wunused-function]
drivers/mfd/as3722.c:438:12: warning: 'as3722_i2c_resume' defined but not used [-Wunused-function]

This marks them both as __maybe_unused, which avoids an ugly #ifdef
and gives us best compile-time coverage. When they are unused, the
compiler will silently drop the functions from its output.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 35deff7e ("mfd: as3722: Handle interrupts on suspend")
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/as3722.c

@@ -424,7 +424,7 @@ static int as3722_i2c_remove(struct i2c_client *i2c)
 	return 0;
 }
 
-static int as3722_i2c_suspend(struct device *dev)
+static int __maybe_unused as3722_i2c_suspend(struct device *dev)
 {
 	struct as3722 *as3722 = dev_get_drvdata(dev);
 
@@ -435,7 +435,7 @@ static int as3722_i2c_suspend(struct device *dev)
 	return 0;
 }
 
-static int as3722_i2c_resume(struct device *dev)
+static int __maybe_unused as3722_i2c_resume(struct device *dev)
 {
 	struct as3722 *as3722 = dev_get_drvdata(dev);