The u3phya_ref clock is already moved into sub-node, and
renamed as ref clock, no used anymore now, so remove it
to avoid confusion
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>