mmc: jz4740: Use clk_prepare_enable/clk_disable_unprepare

In preparation to switching the jz4740 clk driver to the
common clk framework, update the clk enable/disable calls
to clk_prepare_enable/clk_disable_unprepare.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c
index 1c47b347..c4f3872 100644
--- a/drivers/mmc/host/jz4740_mmc.c
+++ b/drivers/mmc/host/jz4740_mmc.c
@@ -626,7 +626,7 @@
 			gpio_set_value(host->pdata->gpio_power,
 					!host->pdata->power_active_low);
 		host->cmdat |= JZ_MMC_CMDAT_INIT;
-		clk_enable(host->clk);
+		clk_prepare_enable(host->clk);
 		break;
 	case MMC_POWER_ON:
 		break;
@@ -634,7 +634,7 @@
 		if (gpio_is_valid(host->pdata->gpio_power))
 			gpio_set_value(host->pdata->gpio_power,
 					host->pdata->power_active_low);
-		clk_disable(host->clk);
+		clk_disable_unprepare(host->clk);
 		break;
 	}