drm/amdgpu: expose the max virtual address

Signed-off-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
index fb428fe..65da7cd 100644
--- a/include/uapi/drm/amdgpu_drm.h
+++ b/include/uapi/drm/amdgpu_drm.h
@@ -560,6 +560,8 @@
 	uint64_t ids_flags;
 	/** Starting virtual address for UMDs. */
 	uint64_t virtual_address_offset;
+	/** The maximum virtual address */
+	uint64_t virtual_address_max;
 	/** Required alignment of virtual addresses. */
 	uint32_t virtual_address_alignment;
 	/** Page table entry - fragment size */