mfd: jz4740-adc: 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: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/jz4740-adc.c b/drivers/mfd/jz4740-adc.c
index 01e86ce..3c0e8cf 100644
--- a/drivers/mfd/jz4740-adc.c
+++ b/drivers/mfd/jz4740-adc.c
@@ -86,13 +86,13 @@
 static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
 {
 	if (atomic_inc_return(&adc->clk_ref) == 1)
-		clk_enable(adc->clk);
+		clk_prepare_enable(adc->clk);
 }
 
 static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
 {
 	if (atomic_dec_return(&adc->clk_ref) == 0)
-		clk_disable(adc->clk);
+		clk_disable_unprepare(adc->clk);
 }
 
 static inline void jz4740_adc_set_enabled(struct jz4740_adc *adc, int engine,