iommu: add capability IOMMU_CAP_NOEXEC

Some IOMMUs accept an IOMMU_NOEXEC protection flag in addition to
IOMMU_READ and IOMMU_WRITE. Expose this as an IOMMU capability.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f47383a..e438b30 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -61,6 +61,7 @@
 	IOMMU_CAP_CACHE_COHERENCY,	/* IOMMU can enforce cache coherent DMA
 					   transactions */
 	IOMMU_CAP_INTR_REMAP,		/* IOMMU supports interrupt isolation */
+	IOMMU_CAP_NOEXEC,		/* IOMMU_NOEXEC flag */
 };
 
 /*