media: atomisp: add debug message to help debugging hmm code

The hmm code is partially based on a fork from 3.10 code,
and has bugs.

Add debug there to help tracking what happens there.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/atomisp/pci/hmm/hmm_bo.c

@@ -1015,6 +1015,11 @@ static int alloc_user_pages(struct hmm_buffer_object *bo,
 		bo->mem_type = HMM_BO_MEM_TYPE_USER;
 	}
 
+	dev_dbg(atomisp_dev, "%s: %d %s pages were allocated as 0x%08x\n",
+		__func__,
+		bo->pgnr,
+		bo->mem_type == HMM_BO_MEM_TYPE_USER ? "user" : "pfn", page_nr);
+
 	/* can be written by caller, not forced */
 	if (page_nr != bo->pgnr) {
 		dev_err(atomisp_dev,