locking, x86, iommu: Annotate qi->q_lock as raw

The qi->q_lock lock can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 19728c4..8b9b5d3 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -271,7 +271,7 @@
 };
 
 struct q_inval {
-	spinlock_t      q_lock;
+	raw_spinlock_t  q_lock;
 	struct qi_desc  *desc;          /* invalidation queue */
 	int             *desc_status;   /* desc status */
 	int             free_head;      /* first free entry */