OsmocomDECT

I have cloned the git repository, and followed this tutorial to get my new kernel built:
​https://wiki.ubuntu.com/KernelTeam/GitKernelBuild

I changed all the values in .config to enable DECT functionality, and this is what I get when I try to compile the kernel:

net/built-in.o: In function `dect_ccp_send_to_cluster':
ccp.c:(.text+0x95e91): undefined reference to `tipc_send_buf'
net/built-in.o: In function `dect_ccp_send_to_cell':
ccp.c:(.text+0x95f31): undefined reference to `tipc_send_buf'
net/built-in.o: In function `dect_ccp_bind_cell':
ccp.c:(.text+0x9656b): undefined reference to `tipc_attach'
ccp.c:(.text+0x965c5): undefined reference to `tipc_createport'
ccp.c:(.text+0x96635): undefined reference to `tipc_send2name'
ccp.c:(.text+0x96657): undefined reference to `tipc_deleteport'
ccp.c:(.text+0x9665f): undefined reference to `tipc_detach'
net/built-in.o: In function `dect_ccp_subscr_rcv':
ccp.c:(.text+0x966fb): undefined reference to `tipc_createport'
ccp.c:(.text+0x96731): undefined reference to `tipc_send2name'
ccp.c:(.text+0x96741): undefined reference to `tipc_deleteport'
net/built-in.o: In function `dect_ccp_cluster_init':
(.text+0x96a3f): undefined reference to `tipc_attach'
net/built-in.o: In function `dect_ccp_cluster_init':
(.text+0x96a96): undefined reference to `tipc_createport'
net/built-in.o: In function `dect_ccp_cluster_init':
(.text+0x96ac5): undefined reference to `tipc_publish'
net/built-in.o: In function `dect_ccp_cluster_init':
(.text+0x96add): undefined reference to `tipc_deleteport'
net/built-in.o: In function `dect_ccp_cluster_init':
(.text+0x96ae5): undefined reference to `tipc_detach'
net/built-in.o: In function `dect_ccp_cl_named_msg':
ccp.c:(.text+0x97235): undefined reference to `tipc_createport'
ccp.c:(.text+0x97245): undefined reference to `tipc_connect2port'
ccp.c:(.text+0x9725a): undefined reference to `tipc_send'
ccp.c:(.text+0x97273): undefined reference to `tipc_disconnect'
ccp.c:(.text+0x9727b): undefined reference to `tipc_deleteport'
net/built-in.o: In function `dect_ccp_unbind_cell':
ccp.c:(.text+0x96524): undefined reference to `tipc_detach'
net/built-in.o: In function `dect_ccp_cluster_shutdown':
(.text+0x96534): undefined reference to `tipc_detach'
make[1]: *** [.tmp_vmlinux1] Error 1
make[1]: Leaving directory `/home/wpld/dect_kernel'
make: *** [debian/stamp-build-kernel] Error 2

I searched for tipc.h files, and found 3 of them:

./include/config/tipc.h
./include/linux/tipc.h
./include/net/tipc/tipc.h

I found out that the linux/tipc.h isn't included in the cpp.c program, however the net/tipc/tipc.h includes it anyway. The problematic functions are all correctly defined in the latter two tipc libraries, but somehow it doesn't work for me.

The config/tipc.h is an empty file.