accel/amdxdna: Preserve user address when PASID is disabled

When PASID is not used, the buffer user address is set to
AMDXDNA_INVALID_ADDR. As a result, heap buffer user address validation
fails even though the original userspace address is available.

Preserve the userspace address regardless of PASID usage so heap buffer
address validation works correctly.

Fixes: dbc8fd7 ("accel/amdxdna: Add expandable device heap support")
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260602040624.2206774-1-lizhi.hou@amd.com

Author: houlz0507

drivers/accel/amdxdna/amdxdna_gem.c

@@ -349,8 +349,11 @@ static int amdxdna_hmm_register(struct amdxdna_gem_obj *abo,
 	u32 nr_pages;
 	int ret;
 
-	if (!amdxdna_pasid_on(abo->client))
+	if (!amdxdna_pasid_on(abo->client)) {
+		/* Need to set uva for heap uva validation */
+		abo->mem.uva = addr;
 		return 0;
+	}
 
 	mapp = kzalloc_obj(*mapp);
 	if (!mapp)