mmc: add the device name in debugging message for supplying vmmc

If vmmc didn't supply, we didn't know which card didn't supply vmmc.
And changed from "put" to "debug".

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

drivers/mmc/mmc.c

@@ -1595,7 +1595,7 @@ static int mmc_power_init(struct mmc *mmc)
 	ret = device_get_supply_regulator(mmc->dev, "vmmc-supply",
 					  &vmmc_supply);
 	if (ret) {
-		puts("No vmmc supply\n");
+		debug("%s: No vmmc supply\n", mmc->dev->name);
 		return 0;
 	}