Add filter linkage test to the Tuner VTS

Test: atest VtsHalTvTunerV1_0TargetTest
Bug: 150953857
Change-Id: Ic98cf1655551623fdc4e4f7e6784faf814adfda5
diff --git a/tv/tuner/1.0/default/Tuner.cpp b/tv/tuner/1.0/default/Tuner.cpp
index 821d83f..ae8070c 100644
--- a/tv/tuner/1.0/default/Tuner.cpp
+++ b/tv/tuner/1.0/default/Tuner.cpp
@@ -139,6 +139,8 @@
 
     DemuxCapabilities caps;
 
+    // IP filter can be an MMTP filter's data source.
+    caps.linkCaps = {0x00, 0x00, 0x02, 0x00, 0x00};
     _hidl_cb(Result::SUCCESS, caps);
     return Void();
 }