Fixed BACDL=none build for makefile building (#213)

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

apps/Makefile

@@ -30,6 +30,9 @@ endif
 ifeq (${BACDL},bip6)
 BACDL_DEFINE=-DBACDL_BIP6=1
 endif
+ifeq (${BACDL},none)
+BACDL_DEFINE=-DBACDL_NONE=1
+endif
 ifeq (${BACDL},)
 BACDL_DEFINE ?= -DBACDL_BIP=1
 BBMD_DEFINE ?= -DBBMD_ENABLED=1 -DBBMD_CLIENT_ENABLED
@@ -150,6 +153,9 @@ PORT_ALL_SRC = \
 	$(PORT_BIP_SRC) \
 	$(PORT_BIP6_SRC)
 
+PORT_NONE_SRC = \
+	$(BACNET_SRC_DIR)/bacnet/datalink/datalink.c
+
 ifeq (${BACDL_DEFINE},-DBACDL_BIP=1)
 BACNET_PORT_SRC = ${PORT_BIP_SRC}
 endif
@@ -165,6 +171,9 @@ endif
 ifeq (${BACDL_DEFINE},-DBACDL_ETHERNET=1)
 BACNET_PORT_SRC = ${PORT_ETHERNET_SRC}
 endif
+ifeq (${BACDL_DEFINE},-DBACDL_NONE=1)
+BACNET_PORT_SRC = ${PORT_NONE_SRC}
+endif
 ifdef BACDL_ALL
 BACNET_PORT_SRC = ${PORT_ALL_SRC}
 endif