ASoC: msm: Add missing backends for Multimedia4

Some backends for the front-end Multimedia4 is missing in the
routing driver. This results tunnel recording failure for
USB headset/BT SCO usecases.

Change-Id: I7998309df4e7da9545bdc75e9b67873cc0417870
Signed-off-by: Krishnankutty Kolathappilly <kkolat@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>