hal: add support to route to line-out device

For line out routing is always set to headphones. Instead
add support to route to line-out device.

Change-Id: Ic8fdba7fd385998d1648df606dbf036d61e131ce
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index 45b02e3..5fc7759 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -3989,6 +3989,8 @@
                 snd_device = SND_DEVICE_OUT_HEADPHONES_44_1;
         } else if (out->format == AUDIO_FORMAT_DSD) {
                 snd_device = SND_DEVICE_OUT_HEADPHONES_DSD;
+        } else if (devices & AUDIO_DEVICE_OUT_LINE) {
+                snd_device = SND_DEVICE_OUT_LINE;
         }  else {
 #ifdef RECORD_PLAY_CONCURRENCY
             if (use_voip_out_devices)