drivers/cpuidle: make cpuidle-ux500.c explicitly non-modular

The Kconfig currently controlling compilation of this code is:

cpuidle/Kconfig.arm:config ARM_U8500_CPUIDLE
cpuidle/Kconfig.arm:    bool "Cpu Idle Driver for the ST-E u8500 processors"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modularity so that when reading the
driver there is no doubt it is builtin-only.

Since module_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/cpuidle-ux500.c

@@ -9,7 +9,7 @@
  * published by the Free Software Foundation.
  */
 
-#include <linux/module.h>
+#include <linux/init.h>
 #include <linux/cpuidle.h>
 #include <linux/spinlock.h>
 #include <linux/atomic.h>
@@ -124,5 +124,4 @@ static struct platform_driver dbx500_cpuidle_plat_driver = {
 	},
 	.probe = dbx500_cpuidle_probe,
 };
-
-module_platform_driver(dbx500_cpuidle_plat_driver);
+builtin_platform_driver(dbx500_cpuidle_plat_driver);