Convert mmc_init to mmc_legacy_init

This is to get it out of the way of incoming MMC framework

Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c
index 473825e..75a75e5 100644
--- a/common/cmd_mmc.c
+++ b/common/cmd_mmc.c
@@ -27,7 +27,7 @@
 
 int do_mmc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 {
-	if (mmc_init (1) != 0) {
+	if (mmc_legacy_init (1) != 0) {
 		printf ("No MMC card found\n");
 		return 1;
 	}