OMAP2/3: GPIO: generalize prepare for idle

Currently, the GPIO 'prepare' hook is only called when going to
off-mode, while the function is called 'prepare_for_retention.'  This
patch renames the function to 'prepare_for_idle' and calls it for any
powersate != PWRDM_POWER_ON passing in the powerstate.

The hook itself is then responsible for doing various preparation
based on the powerstate.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/plat-omap/include/plat/gpio.h b/arch/arm/plat-omap/include/plat/gpio.h
index de7c547..de1c604 100644
--- a/arch/arm/plat-omap/include/plat/gpio.h
+++ b/arch/arm/plat-omap/include/plat/gpio.h
@@ -72,8 +72,8 @@
 				 IH_GPIO_BASE + (nr))
 
 extern int omap_gpio_init(void);	/* Call from board init only */
-extern void omap2_gpio_prepare_for_retention(void);
-extern void omap2_gpio_resume_after_retention(void);
+extern void omap2_gpio_prepare_for_idle(int power_state);
+extern void omap2_gpio_resume_after_idle(void);
 extern void omap_set_gpio_debounce(int gpio, int enable);
 extern void omap_set_gpio_debounce_time(int gpio, int enable);
 extern void omap_gpio_save_context(void);