mxcmmc: decrease minimum frequency to make MMC cards work

This is a temporary workaround until the MMC stack can be fixed.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NPierre Ossman <pierre@ossman.eu>

drivers/mmc/host/mxcmmc.c

@@ -724,7 +724,9 @@ static int mxcmci_probe(struct platform_device *pdev)
 		goto out_clk_put;
 	}
 
-	mmc->f_min = clk_get_rate(host->clk) >> 7;
+	mmc->f_min = clk_get_rate(host->clk) >> 16;
+	if (mmc->f_min < 400000)
+		mmc->f_min = 400000;
 	mmc->f_max = clk_get_rate(host->clk) >> 1;
 
 	/* recommended in data sheet */