gpu: ion: fix carveout ops

when using carveout heap ion_buffer_create function failed because
map_dma and unmap_dma operations aren't set by carveout heap.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion_carveout_heap.c

@@ -142,6 +142,8 @@ static struct ion_heap_ops carveout_heap_ops = {
 	.allocate = ion_carveout_heap_allocate,
 	.free = ion_carveout_heap_free,
 	.phys = ion_carveout_heap_phys,
+	.map_dma = ion_carveout_heap_map_dma,
+	.unmap_dma = ion_carveout_heap_unmap_dma,
 	.map_user = ion_carveout_heap_map_user,
 	.map_kernel = ion_carveout_heap_map_kernel,
 	.unmap_kernel = ion_carveout_heap_unmap_kernel,