kernel/irq: Extend lockdep class for request mutex

The IRQ code already has support for lockdep class for the lock mutex
in an interrupt descriptor. Extend this to add a second class for the
request mutex in the descriptor. Not having a class is resulting in
false positive splats in some code paths.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: linus.walleij@linaro.org
Cc: grygorii.strashko@ti.com
Cc: f.fainelli@gmail.com
Link: https://lkml.kernel.org/r/1512234664-21555-1-git-send-email-andrew@lunn.ch

diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 39fb370..25b33b6 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -255,12 +255,15 @@
 }
 
 static inline void
-irq_set_lockdep_class(unsigned int irq, struct lock_class_key *class)
+irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
+		      struct lock_class_key *request_class)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	if (desc)
-		lockdep_set_class(&desc->lock, class);
+	if (desc) {
+		lockdep_set_class(&desc->lock, lock_class);
+		lockdep_set_class(&desc->request_mutex, request_class);
+	}
 }
 
 #ifdef CONFIG_IRQ_PREFLOW_FASTEOI