mmc: jz4740: Set clock rate to mmc->f_max rather than JZ_MMC_CLK_RATE

The maximum clock rate can be overridden by DT. The clock rate should
be set to the DT-specified value rather than the constant JZ_MMC_CLK_RATE
when this is done. If the maximum clock rate is not set by DT then
mmc->f_max will be set to JZ_MMC_CLK_RATE.

Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/jz4740_mmc.c

@@ -825,7 +825,7 @@ static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
 	int real_rate;
 
 	jz4740_mmc_clock_disable(host);
-	clk_set_rate(host->clk, JZ_MMC_CLK_RATE);
+	clk_set_rate(host->clk, host->mmc->f_max);
 
 	real_rate = clk_get_rate(host->clk);