hwtracing: hisi_ptt: Fix up for "iommu/dma: Make header private"

drivers/hwtracing/ptt/hisi_ptt.c:13:10: fatal error: linux/dma-iommu.h: No such file or directory
   13 | #include <linux/dma-iommu.h>
      |          ^~~~~~~~~~~~~~~~~~~

Caused by:

  commit ff0de066 ("hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device")

interacting with:

  commit f2042ed2 ("iommu/dma: Make header private")

from the iommu tree.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Yicong Yang <yangyicong@hisilicon.com>
[Fixed subject line and added changelog text]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>