ARM: OMAP3/4: consolidate cpuidle Makefile

The current Makefile compiles the cpuidle34xx.c and cpuidle44xx.c files
even if the cpuidle option is not set in the kernel.

This patch fixes this by creating a section in the Makefile where these
files are compiled only if the CONFIG_CPU_IDLE option is set.

This modification breaks an implicit dependency between CPU_IDLE and PM as
they belong to the same block in the Makefile. This is fixed in the Kconfig
by selecting explicitely PM is CPU_IDLE is set.

The linux coding style recommend to use no-op functions in the headers
when the subsystem is disabled instead of adding big section in C files.

This patch fix this also.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 7856489..ab04d3b 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -15,12 +15,25 @@
 
 #include "powerdomain.h"
 
+#ifdef CONFIG_CPU_IDLE
+extern int __init omap3_idle_init(void);
+extern int __init omap4_idle_init(void);
+#else
+static inline int omap3_idle_init(void)
+{
+	return 0;
+}
+
+static inline int omap4_idle_init(void)
+{
+	return 0;
+}
+#endif
+
 extern void *omap3_secure_ram_storage;
 extern void omap3_pm_off_mode_enable(int);
 extern void omap_sram_idle(void);
 extern int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 state);
-extern int omap3_idle_init(void);
-extern int omap4_idle_init(void);
 extern int omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused);
 extern int (*omap_pm_suspend)(void);