ARM: pm-imx5: add clk_prepare/clk_unprepare

It's for migrating to generic clk framework API.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-imx/pm-imx5.c

@@ -89,7 +89,7 @@ void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
 
 static int mx5_suspend_prepare(void)
 {
-	return clk_enable(gpc_dvfs_clk);
+	return clk_prepare_enable(gpc_dvfs_clk);
 }
 
 static int mx5_suspend_enter(suspend_state_t state)
@@ -119,7 +119,7 @@ static int mx5_suspend_enter(suspend_state_t state)
 
 static void mx5_suspend_finish(void)
 {
-	clk_disable(gpc_dvfs_clk);
+	clk_disable_unprepare(gpc_dvfs_clk);
 }
 
 static int mx5_pm_valid(suspend_state_t state)