ioat1: trim ioat_dma_desc_sw

Save 4 bytes per software descriptor by transmitting tx_cnt in an unused
portion of the hardware descriptor.

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

diff --cc drivers/dma/ioat/dma.c
Simple merge

diff --cc drivers/dma/ioat/dma.h
Simple merge

diff --cc drivers/dma/ioat/hw.h
Simple merge