lima: fix xserver page flip fail for full screen client

Need to import client buffer to display drm device, otherwise
get following xserver error log:

[   190.982] (WW) modeset(0): Page flip failed: No such file or directory
[   190.982] (EE) modeset(0): present flip failed

With this fix, full screen x11 client can display its window
buffer directly without a copy. Tested on Allwinner H3, 1080p
full screen glxgears go from 163FPS to 173FPS.

Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Erico Nunes <nunes.erico@gmail.com>
Signed-off-by: Zan Dobersek <zdobersek@igalia.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9038>

src/gallium/drivers/lima/lima_resource.c

@@ -361,6 +361,18 @@ lima_resource_from_handle(struct pipe_screen *pscreen,
    else
       res->levels[0].width = pres->width0;
 
+   if (screen->ro) {
+      /* Make sure that renderonly has a handle to our buffer in the
+       * display's fd, so that a later renderonly_get_handle()
+       * returns correct handles or GEM names.
+       */
+      res->scanout =
+         renderonly_create_gpu_import_for_resource(pres,
+                                                   screen->ro,
+                                                   NULL);
+      /* ignore failiure to allow importing non-displayable buffer */
+   }
+
    return pres;
 
 err_out: