add CPU timer initialization (refs #402)

There is no actual initialization in x86 now.
The initialization rely on hardware reset and Linux initialization.

lib/include/ihk/cpu.h

@@ -104,4 +104,8 @@ extern unsigned int ihk_ikc_irq_apicid;
 
 extern int gettime_local_support;
 
+void init_tick(void);
+void init_delay(void);
+void sync_tick(void);
+
 #endif