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/Makefile b/arch/arm/mach-omap2/Makefile
index fa742f3..6be43ac 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -66,9 +66,7 @@
 obj-$(CONFIG_ARCH_OMAP2)		+= pm24xx.o
 obj-$(CONFIG_ARCH_OMAP2)		+= sleep24xx.o
 obj-$(CONFIG_ARCH_OMAP3)		+= pm34xx.o sleep34xx.o
-obj-$(CONFIG_ARCH_OMAP3)		+= cpuidle34xx.o
 obj-$(CONFIG_ARCH_OMAP4)		+= pm44xx.o omap-mpuss-lowpower.o
-obj-$(CONFIG_ARCH_OMAP4)		+= cpuidle44xx.o
 obj-$(CONFIG_PM_DEBUG)			+= pm-debug.o
 obj-$(CONFIG_OMAP_SMARTREFLEX)          += sr_device.o smartreflex.o
 obj-$(CONFIG_OMAP_SMARTREFLEX_CLASS3)	+= smartreflex-class3.o
@@ -82,6 +80,11 @@
 
 endif
 
+ifeq ($(CONFIG_CPU_IDLE),y)
+obj-$(CONFIG_ARCH_OMAP3)                += cpuidle34xx.o
+obj-$(CONFIG_ARCH_OMAP4)                += cpuidle44xx.o
+endif
+
 # PRCM
 obj-y					+= prm_common.o
 obj-$(CONFIG_ARCH_OMAP2)		+= prcm.o cm2xxx_3xxx.o prm2xxx_3xxx.o