iommu: Stop exporting iommu_map_sg_atomic()

Function iommu_map_sg_atomic() is only referenced in dma-iommu.c, which
can only be built-in, so stop exporting.
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/1609940111-28563-5-git-send-email-john.garry@huawei.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/iommu.c

@@ -2586,7 +2586,6 @@ size_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova,
 {
 	return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC);
 }
-EXPORT_SYMBOL_GPL(iommu_map_sg_atomic);
 
 int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr,
 			       phys_addr_t paddr, u64 size, int prot)