mmc: change the set_ios return type from void to int

To maintain consistency, set_ios type of legacy mmc_ops changed to int.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/mvebu_mmc.c b/drivers/mmc/mvebu_mmc.c
index a2792ac..3c7fb21 100644
--- a/drivers/mmc/mvebu_mmc.c
+++ b/drivers/mmc/mvebu_mmc.c
@@ -316,12 +316,14 @@
 	mvebu_mmc_write(SDIO_HOST_CTRL, ctrl_reg);
 }
 
-static void mvebu_mmc_set_ios(struct mmc *mmc)
+static int mvebu_mmc_set_ios(struct mmc *mmc)
 {
 	debug("%s: bus[%d] clock[%d]\n", DRIVER_NAME,
 	      mmc->bus_width, mmc->clock);
 	mvebu_mmc_set_bus(mmc->bus_width);
 	mvebu_mmc_set_clk(mmc->clock);
+
+	return 0;
 }
 
 /*