ASoC: msm: qdsp6v2: add path to support external EC reference

Addition of a routing path to connect VOICE2
uplink with MI2S Tx port. This change is required if
external EC is to be used.

CRs-Fixed: 723640
Change-Id: Idebb463467ee8f371cb3c0f76b0f30fd260e88da
Signed-off-by: Aravind Kumar <akumark@codeaurora.org>