ARM: dma-mapping: Add arm_iommu_detach_device()

A counter part of arm_iommu_attach_device().

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-iommu.h
index 666d8a8..a8c56ac 100644
--- a/arch/arm/include/asm/dma-iommu.h
+++ b/arch/arm/include/asm/dma-iommu.h
@@ -30,6 +30,7 @@
 
 int arm_iommu_attach_device(struct device *dev,
 					struct dma_iommu_mapping *mapping);
+void arm_iommu_detach_device(struct device *dev);
 
 #endif /* __KERNEL__ */
 #endif