[PATCH -next] mfd: rk808: Mark rk8xx_resume and rk8xx_suspend as __maybe_unused

[YueHaibing]

Fix build warning:

drivers/mfd/rk808.c:752:12: warning: 'rk8xx_resume' defined but not used [-Wunused-function]
drivers/mfd/rk808.c:732:12: warning: 'rk8xx_suspend' defined but not used [-Wunused-function]

The function is declared unconditionally but only called
while CONFIG_PM_SLEEP is set.

Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
---
 drivers/mfd/rk808.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/rk808.c b/drivers/mfd/rk808.c
index 601cefb..9a9e631 100644
--- a/drivers/mfd/rk808.c
+++ b/drivers/mfd/rk808.c
@@ -729,7 +729,7 @@ static int rk808_remove(struct i2c_client *client)
 	return 0;
 }
 
-static int rk8xx_suspend(struct device *dev)
+static int __maybe_unused rk8xx_suspend(struct device *dev)
 {
 	struct rk808 *rk808 = i2c_get_clientdata(rk808_i2c_client);
 	int ret = 0;
@@ -749,7 +749,7 @@ static int rk8xx_suspend(struct device *dev)
 	return ret;
 }
 
-static int rk8xx_resume(struct device *dev)
+static int __maybe_unused rk8xx_resume(struct device *dev)
 {
 	struct rk808 *rk808 = i2c_get_clientdata(rk808_i2c_client);
 	int ret = 0;
-- 
2.7.4