ARM: dts: qcom: vm: Add device nodes for second AFE rx and proxy tx devices

    * Add afe_proxy_tx_2 node for proxy capture frontend device.
    * Add afe_pcm_rx_2 node for afe playback backend device.
    * Add the new nodes to the ADP soundcard.

Change-Id: Ie0f64fcbd1ff1d86107985a8ebe8c84776d2fb0f
Signed-off-by: Han Lu <hanlu@codeaurora.org>