ARM: davinci: convert platform code to use clk_prepare/clk_unprepare

As a first step towards migrating davinci platforms to use common clock
framework, replace all instances of clk_enable() with clk_prepare_enable()
and clk_disable() with clk_disable_unprepare(). Until the platform is
switched to use the CONFIG_HAVE_CLK_PREPARE Kconfig variable, this just
adds a might_sleep() call and would work without any issues.

This will make it easy later to switch to common clk based implementation
of clk driver from DaVinci specific driver.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Reviewed-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
index 75da315..9847938 100644
--- a/arch/arm/mach-davinci/time.c
+++ b/arch/arm/mach-davinci/time.c
@@ -379,7 +379,7 @@
 
 	timer_clk = clk_get(NULL, "timer0");
 	BUG_ON(IS_ERR(timer_clk));
-	clk_enable(timer_clk);
+	clk_prepare_enable(timer_clk);
 
 	/* init timer hw */
 	timer_init();
@@ -429,7 +429,7 @@
 	wd_clk = clk_get(&pdev->dev, NULL);
 	if (WARN_ON(IS_ERR(wd_clk)))
 		return;
-	clk_enable(wd_clk);
+	clk_prepare_enable(wd_clk);
 
 	/* disable, internal clock source */
 	__raw_writel(0, base + TCR);