gpio: davinci: preparation for switch to common clock framework

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>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-davinci.c

@@ -366,7 +366,7 @@ static int __init davinci_gpio_irq_setup(void)
 		       PTR_ERR(clk));
 		return PTR_ERR(clk);
 	}
-	clk_enable(clk);
+	clk_prepare_enable(clk);
 
 	/* Arrange gpio_to_irq() support, handling either direct IRQs or
 	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct