bullhead: Add wifi HAL to vintf

Bug: 36886769
Test: compiles (assemble_vintf checks this is formatted correctly and 
works with compatibility matrix)
Change-Id: Ib3315ffabf08ab1c96325958408558e867eefdd8
(cherry picked from commit e3ce2c97d2a4449258673f00b95b3d9040fc8d8b)
diff --git a/manifest.xml b/manifest.xml
index 9759eba..6221e0a 100644
--- a/manifest.xml
+++ b/manifest.xml
@@ -8,4 +8,13 @@
             <instance>default</instance>
         </interface>
     </hal>
+    <hal format="hidl">
+        <name>android.hardware.wifi</name>
+        <transport>hwbinder</transport>
+        <version>1.0</version>
+        <interface>
+            <name>IWifi</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
 </manifest>