hal: Add support for 8939 sound cards

-Add entries for 8939 sound card names
 to load the mixer controls for 8939

Change-Id: Iadc4764071d0eb790906b62d94043c2e5d93937e
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index c71706c..462577c 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -412,6 +412,10 @@
                  sizeof("msm8x16-skui-snd-card"))) {
         strlcpy(mixer_xml_path, MIXER_XML_PATH_QRD_SKUI,
                 sizeof(MIXER_XML_PATH_QRD_SKUI));
+    } if (!strncmp(snd_card_name, "msm8939-snd-card-mtp",
+                 sizeof("msm8939-snd-card-mtp"))) {
+        strlcpy(mixer_xml_path, MIXER_XML_PATH,
+                sizeof(MIXER_XML_PATH));
     } else {
         strlcpy(mixer_xml_path, MIXER_XML_PATH,
                 sizeof(MIXER_XML_PATH));