angler: Add paths for bt-sco echo reference

Add paths for bt-sco echo refererence
Bug: 29581152

Change-Id: Ie7fbfd29b2adb938c9a0a7cf92e2b5801dff71b1
diff --git a/mixer_paths.xml b/mixer_paths.xml
index 03ed27c..96f3722 100755
--- a/mixer_paths.xml
+++ b/mixer_paths.xml
@@ -422,6 +422,18 @@
         <ctl name="AUDIO_REF_EC_UL1 MUX" value="QUAT_MI2S_RX" />
     </path>
 
+    <path name="bt-sco-echo-reference">
+        <ctl name="AUDIO_REF_EC_UL1 MUX" value="SEC_AUX_PCM_RX" />
+    </path>
+
+    <path name="echo-reference bt-sco">
+        <path name="bt-sco-echo-reference" />
+    </path>
+
+    <path name="echo-reference bt-sco-wb">
+        <path name="bt-sco-echo-reference" />
+    </path>
+
     <path name="deep-buffer-playback hdmi">
         <ctl name="HDMI Mixer MultiMedia1" value="1" />
     </path>