mmc: display mmc list information like mmc_legacy type

It's nicer to see this:

=> mmc list
dwmmc@ff0c0000: 0
dwmmc@ff0f0000: 1 (eMMC)

than this:

=> mmc list
dwmmc@ff0c0000: 0dwmmc@ff0f0000: 1 (eMMC)

With the former, it's much clearer which mmc devices are on.

Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>

drivers/mmc/mmc-uclass.c

@@ -169,7 +169,7 @@ void print_mmc_devices(char separator)
 
 	for (uclass_first_device(UCLASS_MMC, &dev);
 	     dev;
-	     uclass_next_device(&dev)) {
+	     uclass_next_device(&dev), first = false) {
 		struct mmc *m = mmc_get_mmc_dev(dev);
 
 		if (!first) {