clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR

There's no Kconfig symbol GENERIC_CLOCKEVENTS_MIGR, so the check for it
will always fail.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kernel/time/Kconfig

@@ -25,7 +25,7 @@ config HIGH_RES_TIMERS
 config GENERIC_CLOCKEVENTS_BUILD
 	bool
 	default y
-	depends on GENERIC_CLOCKEVENTS || GENERIC_CLOCKEVENTS_MIGR
+	depends on GENERIC_CLOCKEVENTS
 
 config GENERIC_CLOCKEVENTS_MIN_ADJUST
 	bool