[S390] Convert s390 to GENERIC_CLOCKEVENTS.

This way we get rid of s390's NO_IDLE_HZ and use the generic dynticks
variant instead. In addition we get high resolution timers for free.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index da6ea64..f6a68e1 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -43,6 +43,9 @@
 config GENERIC_TIME
 	def_bool y
 
+config GENERIC_CLOCKEVENTS
+	def_bool y
+
 config GENERIC_BUG
 	bool
 	depends on BUG
@@ -73,6 +76,8 @@
 
 comment "Processor type and features"
 
+source "kernel/time/Kconfig"
+
 config 64BIT
 	bool "64 bit kernel"
 	help
@@ -487,25 +492,6 @@
 
 source kernel/Kconfig.hz
 
-config NO_IDLE_HZ
-	bool "No HZ timer ticks in idle"
-	help
-	  Switches the regular HZ timer off when the system is going idle.
-	  This helps z/VM to detect that the Linux system is idle. VM can
-	  then "swap-out" this guest which reduces memory usage. It also
-	  reduces the overhead of idle systems.
-
-	  The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
-	  hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
-	  timer is active.
-
-config NO_IDLE_HZ_INIT
-	bool "HZ timer in idle off by default"
-	depends on NO_IDLE_HZ
-	help
-	  The HZ timer is switched off in idle by default. That means the
-	  HZ timer is already disabled at boot time.
-
 config S390_HYPFS_FS
 	bool "s390 hypervisor file system support"
 	select SYS_HYPERVISOR