hal: support HFP volume mixer in audio platform info

Add support to get HFP volume mixer control from
audio_platform_info.xml.

Bug: 29971368

Change-Id: I6f3a718ccaf2518826c756d043204165a19ca820
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index a1d1e20..683723f 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -2037,6 +2037,8 @@
         list_add_tail(&operator_info_list, &info->list);
         ALOGV("%s: add operator[%s] mccmnc[%s]", __func__, info->name, info->mccmnc);
     }
+
+    audio_extn_hfp_set_parameters(my_data->adev, parms);
 done:
     ALOGV("%s: exit with code(%d)", __func__, ret);
     if (kv_pairs != NULL)