mmc: fix to assign to correct clock value when clock is enabling

When clock is enabling, it's assigned to 0 as mmc->clock.
Then it can't initialize any card.
Fix to assign to correct clock value as mmc->cfg->f_min or f_max.

Fixes: 9546eb92cb6 ("mmc: fix the wrong disabling clock")
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Guillaume GARDET <guillaume.gardet@free.fr>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

drivers/mmc/mmc.c

@@ -1501,7 +1501,7 @@ static int mmc_set_ios(struct mmc *mmc)
 
 int mmc_set_clock(struct mmc *mmc, uint clock, bool disable)
 {
-	if (!disable && clock != 0) {
+	if (!disable) {
 		if (clock > mmc->cfg->f_max)
 			clock = mmc->cfg->f_max;