v3d: fix dest offset in TFU setup

It is using the source level instead of the destiny level (base_level)
to compute the dest offset.

This fixes `framebuffer-blit-levels draw rgba -auto -fbo` piglit test.

Fixes: 976ea90b ("v3d: Add support for using the TFU to do some blits.")
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <!8491>

src/gallium/drivers/v3d/v3d_blit.c

@@ -277,7 +277,7 @@ v3d_tfu(struct pipe_context *pctx,
         }
 
         uint32_t dst_offset = (dst->bo->offset +
-                               v3d_layer_offset(pdst, src_level, dst_layer));
+                               v3d_layer_offset(pdst, base_level, dst_layer));
         tfu.ioa |= dst_offset;
         if (last_level != base_level)
                 tfu.ioa |= V3D_TFU_IOA_DIMTW;