mmc: dw_mmc: fix sparse non static symbol warning

Fixes the following sparse warning:

drivers/mmc/host/dw_mmc-k3.c:116:1: warning:
 symbol 'dw_mci_k3_pmops' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Chris Ball <chris@printf.net>

drivers/mmc/host/dw_mmc-k3.c

@@ -113,7 +113,7 @@ static int dw_mci_k3_resume(struct device *dev)
 	return dw_mci_resume(host);
 }
 
-SIMPLE_DEV_PM_OPS(dw_mci_k3_pmops, dw_mci_k3_suspend, dw_mci_k3_resume);
+static SIMPLE_DEV_PM_OPS(dw_mci_k3_pmops, dw_mci_k3_suspend, dw_mci_k3_resume);
 
 static struct platform_driver dw_mci_k3_pltfm_driver = {
 	.probe		= dw_mci_k3_probe,