audio: Fix the device switch delay issue during voice call

- During voice call, the device switch from earpiece to speaker or
  vice versa takes more than 3.5sec which is not acceptable.
- The mixer controls for speaker devices are incorrect which results
  slimbus errors while switching from speaker to earpiece.
- Corrected the speaker device mixer controls to fix the issue.

Change-Id: I202f3389c85368f47a0b2690c037423baa50d280
diff --git a/mixer_paths.xml b/mixer_paths.xml
index 65e6961..d0e9e98 100644
--- a/mixer_paths.xml
+++ b/mixer_paths.xml
@@ -266,15 +266,11 @@
     </path>
 
     <path name="speaker">
-        <ctl name="SLIM_0_RX Channels" value="Two" />
+        <ctl name="SLIM_0_RX Channels" value="One" />
         <ctl name="RX3 MIX1 INP1" value="RX1" />
         <ctl name="RX3 MIX1 INP2" value="RX6" />
-        <ctl name="RX5 MIX1 INP1" value="RX2" />
-        <ctl name="RX5 MIX1 INP2" value="RX7" />
         <ctl name="RX4 DSM MUX" value="DSM_INV" />
-        <ctl name="RX6 DSM MUX" value="DSM_INV" />
         <ctl name="SLIM TX3 MUX" value="RMIX1" />
-        <ctl name="SLIM TX5 MUX" value="RMIX2" />
     </path>
 
     <path name="speaker-mic">