clocksource/drivers/integrator-ap: Add the COMPILE_TEST option

Change the Kconfig option logic to fullfil with the current approach.

A new Kconfig option is added, CONFIG_INTEGRATOR_AP_TIMER and is selected
by the platform. Then the clocksource's Kconfig is changed to make this
option selectable by the user if the COMPILE_TEST option is set. Otherwise,
it is up to the platform's Kconfig to select the timer.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

arch/arm/mach-integrator/Kconfig

@@ -20,7 +20,7 @@ if ARCH_INTEGRATOR
 
 config ARCH_INTEGRATOR_AP
 	bool "Support Integrator/AP and Integrator/PP2 platforms"
-	select CLKSRC_MMIO
+	select INTEGRATOR_AP_TIMER
 	select MIGHT_HAVE_PCI
 	select SERIAL_AMBA_PL010 if TTY
 	select SERIAL_AMBA_PL010_CONSOLE if TTY

drivers/clocksource/Kconfig

@@ -214,6 +214,13 @@ config KEYSTONE_TIMER
 	help
 	  Enables support for the Keystone timer.
 
+config INTEGRATOR_AP_TIMER
+	bool "Integrator-ap timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Integrator-ap timer.
+
 config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
 	bool "Clocksource PRCMU Timer sched_clock"
 	depends on (CLKSRC_DBX500_PRCMU && !CLKSRC_NOMADIK_MTU_SCHED_CLOCK)

drivers/clocksource/Makefile

@@ -57,7 +57,7 @@ obj-$(CONFIG_ARM_TIMER_SP804)		+= timer-sp804.o
 obj-$(CONFIG_CLKSRC_METAG_GENERIC)	+= metag_generic.o
 obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)	+= dummy_timer.o
 obj-$(CONFIG_KEYSTONE_TIMER)		+= timer-keystone.o
-obj-$(CONFIG_ARCH_INTEGRATOR_AP)	+= timer-integrator-ap.o
+obj-$(CONFIG_INTEGRATOR_AP_TIMER)	+= timer-integrator-ap.o
 obj-$(CONFIG_CLKSRC_VERSATILE)		+= versatile.o
 obj-$(CONFIG_CLKSRC_MIPS_GIC)		+= mips-gic-timer.o
 obj-$(CONFIG_CLKSRC_TANGO_XTAL)		+= tango_xtal.o