etnaviv: increment correct seqno for external resources

If we import a dma-buf with a sampler/pixel pipe incompatible modifier,
the imported buffer will end up in an external resource view. As
resource_changed signals the change of the imported resource, we need
to update the external view seqno, instead of the base resource seqno.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Wladimir J. van der Laan <laanwj@gmail.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>

src/gallium/drivers/etnaviv/etnaviv_resource.c

@@ -305,7 +305,10 @@ etna_resource_changed(struct pipe_screen *pscreen, struct pipe_resource *prsc)
 {
    struct etna_resource *res = etna_resource(prsc);
 
-   res->seqno++;
+   if (res->external)
+      etna_resource(res->external)->seqno++;
+   else
+      res->seqno++;
 }
 
 static void