qurt cmake dependency fixes

platforms/qurt/src/px4_layer/CMakeLists.txt

@@ -57,4 +57,5 @@ add_library(px4_layer
 	${QURT_LAYER_SRCS}
 	${CONFIG_SRC}
 )
+target_link_libraries(px4_layer PRIVATE work_queue)
 add_dependencies(px4_layer uorb_msgs) # dataman requires mission

platforms/qurt/src/px4_layer/px4_qurt_impl.cpp

@@ -166,3 +166,9 @@ int fputc(int c, FILE *stream)
 {
 	return c;
 }
+
+int putchar(int character)
+{
+	PX4_ERR("Error: Calling unresolved symbol stub:[%s]", __FUNCTION__);
+	return character;
+}