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

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 <[email protected]>
Tested-by: Guillaume GARDET <[email protected]>
Tested-by: Anand Moon <[email protected]>
Tested-by: Stephen Warren <[email protected]>