ioat1: kill unused unmap parameters

The unified ioat1/ioat2 ioat_dma_unmap() implementation derives the
source and dest addresses from the unmap descriptor.  There is no longer
a need to track this information in struct ioat_desc_sw.

Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/ioat/dma.h

@@ -179,8 +179,6 @@ struct ioat_desc_sw {
 	struct list_head node;
 	int tx_cnt;
 	size_t len;
-	dma_addr_t src;
-	dma_addr_t dst;
 	struct dma_async_tx_descriptor txd;
 };