frontends/va: add surface alignment attribute

It is only taking effect in hevc encoding so far.

Cc: mesa-stable
Reviewed-By: Sil Vilerino <sivileri@microsoft.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Ruijing Dong <ruijing.dong@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28280>

src/gallium/frontends/va/surface.c

@@ -725,6 +725,16 @@ vlVaQuerySurfaceAttributes(VADriverContextP ctx, VAConfigID config_id,
                                   config->profile, config->entrypoint,
                                   PIPE_VIDEO_CAP_MAX_HEIGHT);
       i++;
+#if VA_CHECK_VERSION(1, 21, 0)
+      attribs[i].type = VASurfaceAttribAlignmentSize;
+      attribs[i].value.type = VAGenericValueTypeInteger;
+      attribs[i].flags = VA_SURFACE_ATTRIB_GETTABLE;
+      attribs[i].value.value.i =
+         pscreen->get_video_param(pscreen,
+                                  config->profile, config->entrypoint,
+                                  PIPE_VIDEO_CAP_ENC_SURFACE_ALIGNMENT);
+      i++;
+#endif
    } else {
       attribs[i].type = VASurfaceAttribMaxWidth;
       attribs[i].value.type = VAGenericValueTypeInteger;