clocksource: Add new CLKSRC_{PROBE,ACPI} config symbols

The clocksource probing infrastructure currently depends on
CONFIG_CLKSRC_OF, which depends on CONFIG_OF. In order to make
this infrastructure selectable even if CONFIG_OF is not selected,
introduce a new CONFIG_CLKSRC_PROBE (which allow the infrastructure
to be compiled in), and CONFIG_CLKSRC_ACPI (which is the pendent
of CONFIG_CLKSRC_OF for ACPI).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/clocksource/Kconfig

@@ -2,6 +2,14 @@ menu "Clock Source drivers"
 
 config CLKSRC_OF
 	bool
+	select CLKSRC_PROBE
+
+config CLKSRC_ACPI
+	bool
+	select CLKSRC_PROBE
+
+config CLKSRC_PROBE
+	bool
 
 config CLKSRC_I8253
 	bool

drivers/clocksource/Makefile

@@ -1,4 +1,4 @@
-obj-$(CONFIG_CLKSRC_OF)	+= clksrc-of.o
+obj-$(CONFIG_CLKSRC_PROBE)	+= clksrc-of.o
 obj-$(CONFIG_ATMEL_PIT)		+= timer-atmel-pit.o
 obj-$(CONFIG_ATMEL_ST)		+= timer-atmel-st.o
 obj-$(CONFIG_ATMEL_TCB_CLKSRC)	+= tcb_clksrc.o

include/linux/clocksource.h

@@ -246,7 +246,7 @@ extern int clocksource_i8253_init(void);
 #define CLOCKSOURCE_OF_DECLARE(name, compat, fn) \
 	OF_DECLARE_1(clksrc, name, compat, fn)
 
-#ifdef CONFIG_CLKSRC_OF
+#ifdef CONFIG_CLKSRC_PROBE
 extern void clocksource_of_init(void);
 #else
 static inline void clocksource_of_init(void) {}