VOL-1248 OpenOLT Agent - Fix linker error

Change-Id: I33e65608601292cdc21adab204b839626295cacf
diff --git a/Makefile.in b/Makefile.in
index 8859da8..1f15760 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -227,7 +227,7 @@
 .DEFAULT_GOAL := all
 all: $(BUILD_DIR)/openolt
 $(BUILD_DIR)/openolt: sdk protos $(OBJS)
-	$(CXX) -pthread $(LDFLAGS) -L$(BALLIBDIR) $(OBJS) $(OPENOLT_API_LIB) $(LIBPROTOBUF_PATH)/libprotobuf.a -o $@ -l$(BALLIBNAME)
+	$(CXX) $(LDFLAGS) -L$(BALLIBDIR) $(OBJS) $(OPENOLT_API_LIB) $(LIBPROTOBUF_PATH)/libprotobuf.a -o $@ -l$(BALLIBNAME) $(shell pkg-config --libs protobuf grpc++ grpc)
 	ln -sf $(PWD)/$(BAL_DIR)/bcm68620_release/$(DEVICE)/release/release_$(DEVICE)_V$(BAL_MAJOR_VER).$(DEV_VER).tar.gz $(BUILD_DIR)/.
 	ln -sf $(PWD)/$(BAL_DIR)/bcm68620_release/$(DEVICE)/release/broadcom/libbal_api_dist.so $(BUILD_DIR)/.
 	ln -sf $(PWD)/$(BAL_DIR)/bal_release/build/core/src/apps/bal_core_dist/bal_core_dist $(BUILD_DIR)/.