Remove DEBUG_SEMAPHORE from Kconfig

Alpha and FRV mutexes had an option to print lots of debugging messages
in their semaphore implementation.  This feature has not been carried
over to the generic semaphores, so remove the stale Kconfig option.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>

lib/Kconfig.debug

@@ -265,16 +265,6 @@ config DEBUG_MUTEXES
 	 This feature allows mutex semantics violations to be detected and
 	 reported.
 
-config DEBUG_SEMAPHORE
-	bool "Semaphore debugging"
-	depends on DEBUG_KERNEL
-	depends on ALPHA || FRV
-	default n
-	help
-	  If you say Y here then semaphore processing will issue lots of
-	  verbose debugging messages.  If you suspect a semaphore problem or a
-	  kernel hacker asks for this option then say Y.  Otherwise say N.
-
 config DEBUG_LOCK_ALLOC
 	bool "Lock debugging: detect incorrect freeing of live locks"
 	depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT