ASoC: msm: qdsp6v2: Fix uplink mute in voice call when Vbat is enabled

Uplink mute observed in voice call when Vbat is enabled. This is due
to external echo reference port "SLIMBUS_1_TX" is not started, as it
is not connected to any of the voice front end DAI links. Fix this
issue by updating dapm route map b/w SLIMBUS_1_TX and voice front end
DAI links.

Change-Id: I02ffbb2565deed073909d49b3fb20548bc406daa
Signed-off-by: Venkata Narendra Kumar Gutta <vgutta@codeaurora.org>