gpu: ion: Add support for iommus

Add infrastructure to support mapping allocations
into iommus.

Change-Id: Ia5eafebee408e297013bf55284abf67d9eb8d78b
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/drivers/gpu/ion/Makefile b/drivers/gpu/ion/Makefile
index c0a47d8..3911950 100644
--- a/drivers/gpu/ion/Makefile
+++ b/drivers/gpu/ion/Makefile
@@ -1,3 +1,3 @@
-obj-$(CONFIG_ION) +=	ion.o ion_heap.o ion_system_heap.o ion_carveout_heap.o
+obj-$(CONFIG_ION) +=	ion.o ion_heap.o ion_system_heap.o ion_carveout_heap.o ion_iommu_heap.o
 obj-$(CONFIG_ION_TEGRA) += tegra/
 obj-$(CONFIG_ION_MSM) += msm/