Add displayservice.

This hidl service provides information about vsync and hotplug
to vendor services which is required by at least some camera
hal implementations.

Test: VtsFwkDisplayServiceV1_0TargetTest
Bug: 38311538
Change-Id: Ifc344c11ca4b3c8cebc6f0145f506d1aa774506d
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 7bb20ba..535c930 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -133,11 +133,13 @@
     main_surfaceflinger.cpp
 
 LOCAL_SHARED_LIBRARIES := \
+    android.frameworks.displayservice@1.0 \
     android.hardware.configstore@1.0 \
     android.hardware.configstore-utils \
     android.hardware.graphics.allocator@2.0 \
     libsurfaceflinger \
     libcutils \
+    libdisplayservicehidl \
     liblog \
     libbinder \
     libhidlbase \