fsl_esdhc: Fix max clock frequency

The max clock of MMC is 52MHz

Signed-off-by: Jerry Huang <Changm-Ming.Huang@freescale.com>
Tested-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index 73d5cd3..7bab2f6 100644
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -477,7 +477,7 @@
 		mmc->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
 
 	mmc->f_min = 400000;
-	mmc->f_max = MIN(gd->sdhc_clk, 50000000);
+	mmc->f_max = MIN(gd->sdhc_clk, 52000000);
 
 	mmc_register(mmc);