hal: add get_parameter support slowtalk

Add support for get_parameter so that slow talk
value can be retrieved by apps.

CRs-Fixed: 579154
Change-Id: Ia91e1ec1ac2e5b71041332529ef3d871e04800c3
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index 352c4d8..486943c 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -1366,6 +1366,14 @@
         str_parms_add_str(reply, AUDIO_PARAMETER_KEY_FLUENCE_TYPE, value);
     }
 
+    memset(value, 0, sizeof(value));
+    ret = str_parms_get_str(query, AUDIO_PARAMETER_KEY_SLOWTALK,
+                            value, sizeof(value));
+    if (ret >= 0) {
+        str_parms_add_int(reply, AUDIO_PARAMETER_KEY_SLOWTALK,
+                          my_data->slowtalk);
+    }
+
     ALOGV("%s: exit: returns - %s", __func__, str_parms_to_str(reply));
 }