rt_mutex: Add lockdep annotations

Now that (PI) futexes have their own private RT-mutex interface and
implementation we can easily add lockdep annotations to the existing
RT-mutex interface.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

lib/Kconfig.debug

@@ -1052,6 +1052,7 @@ config DEBUG_LOCK_ALLOC
 	depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 	select DEBUG_SPINLOCK
 	select DEBUG_MUTEXES
+	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select LOCKDEP
 	help
 	 This feature will check whether any held lock (spinlock, rwlock,
@@ -1067,6 +1068,7 @@ config PROVE_LOCKING
 	select LOCKDEP
 	select DEBUG_SPINLOCK
 	select DEBUG_MUTEXES
+	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select DEBUG_LOCK_ALLOC
 	select TRACE_IRQFLAGS
 	default n
@@ -1121,6 +1123,7 @@ config LOCK_STAT
 	select LOCKDEP
 	select DEBUG_SPINLOCK
 	select DEBUG_MUTEXES
+	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select DEBUG_LOCK_ALLOC
 	default n
 	help