powerpc/macio: Ensure all dma routines get copied over

Also add a comment to dev_archdata, indicating that changes there need
to be verified against the driver code.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index a3954e4..16d25c0 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -9,6 +9,12 @@
 struct dma_map_ops;
 struct device_node;
 
+/*
+ * Arch extensions to struct device.
+ *
+ * When adding fields, consider macio_add_one_device in
+ * drivers/macintosh/macio_asic.c
+ */
 struct dev_archdata {
 	/* DMA operations on that device */
 	struct dma_map_ops	*dma_ops;