freedreno/drm: pipe should hold reference to device

A more direct solution would be for bo's to have a reference to the
device.  But bo's are ref/unrefd more frequently.

This avoids async submits unrefing a bo after the device handle-
table is freed.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10444>

src/freedreno/drm/freedreno_pipe.c

@@ -53,7 +53,7 @@ fd_pipe_new2(struct fd_device *dev, enum fd_pipe_id id, uint32_t prio)
       return NULL;
    }
 
-   pipe->dev = dev;
+   pipe->dev = fd_device_ref(dev);
    pipe->id = id;
    p_atomic_set(&pipe->refcnt, 1);
 
@@ -114,6 +114,7 @@ fd_pipe_del_locked(struct fd_pipe *pipe)
    if (!p_atomic_dec_zero(&pipe->refcnt))
       return;
    fd_bo_del_locked(pipe->control_mem);
+   fd_device_del_locked(pipe->dev);
    pipe->funcs->destroy(pipe);
 }