[PATCH -next v2] usb: cdns3: imx: mark cdns_imx_system_resume as __maybe_unused

['Wei Yongjun]

From: Wei Yongjun <weiyongjun1 at huawei.com>

The function cdns_imx_system_resume() may have no callers depending
on configuration, so it must be marked __maybe_unused to avoid
harmless warning:

drivers/usb/cdns3/cdns3-imx.c:378:12: warning:
 'cdns_imx_system_resume' defined but not used [-Wunused-function]
  378 | static int cdns_imx_system_resume(struct device *dev)
      |            ^~~~~~~~~~~~~~~~~~~~~~

Fixes: 67982dfa59de ("usb: cdns3: imx: add power lost support for system resume")
Reported-by: Hulk Robot <hulkci at huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1 at huawei.com>
---
 drivers/usb/cdns3/cdns3-imx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/cdns3/cdns3-imx.c b/drivers/usb/cdns3/cdns3-imx.c
index 708b51cc5844..74e758dc0895 100644
--- a/drivers/usb/cdns3/cdns3-imx.c
+++ b/drivers/usb/cdns3/cdns3-imx.c
@@ -375,7 +375,7 @@ static inline bool cdns_imx_is_power_lost(struct cdns_imx *data)
 		return false;
 }
 
-static int cdns_imx_system_resume(struct device *dev)
+static int __maybe_unused cdns_imx_system_resume(struct device *dev)
 {
 	struct cdns_imx *data = dev_get_drvdata(dev);
 	int ret;