mmc: dw_mmc: Make dw_mci_exynos_probe static

Silences the following sparse warning:
drivers/mmc/host/dw_mmc-exynos.c:218:5: warning:
symbol 'dw_mci_exynos_probe' was not declared. Should it be static?
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Acked-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

drivers/mmc/host/dw_mmc-exynos.c

@@ -215,7 +215,7 @@ static const struct of_device_id dw_mci_exynos_match[] = {
 };
 MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
 
-int dw_mci_exynos_probe(struct platform_device *pdev)
+static int dw_mci_exynos_probe(struct platform_device *pdev)
 {
 	const struct dw_mci_drv_data *drv_data;
 	const struct of_device_id *match;