ARM: imx: cpuidle: use init/exit common routine

The code intializes the cpuidle driver at different places.
The cpuidle driver for :
  * imx5 : is in the pm-imx5.c, the init function is in cpuidle.c
  * imx6 : is in cpuidle-imx6q.c, the init function is in cpuidle.c
           and cpuidle-imx6q.c

Instead of having the cpuidle code spread across different files,
let's create a driver for each SoC and use the common register function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

arch/arm/mach-imx/cpuidle.h

@@ -10,18 +10,16 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
-#include <linux/cpuidle.h>
-
 #ifdef CONFIG_CPU_IDLE
-extern int imx_cpuidle_init(struct cpuidle_driver *drv);
+extern int imx5_cpuidle_init(void);
 extern int imx6q_cpuidle_init(void);
 #else
-static inline int imx_cpuidle_init(struct cpuidle_driver *drv)
+static inline int imx5_cpuidle_init(void)
 {
-	return -ENODEV;
+	return 0;
 }
 static inline int imx6q_cpuidle_init(void)
 {
-	return -ENODEV;
+	return 0;
 }
 #endif