There's No KDBUS (Or BUS1) For The Linux 4.5 Kernel
Hopefully you weren't counting on KDBUS for Linux 4.5 as it wasn't really expected and would have been more surprising if a pull request had been sent in. That's because KDBUS was sent back to the drawing board and stripped out of Fedora Rawhide's kernel after initially being proposed for mainline integration and systemd developers encouraging Linux distributions to try out the code within their kernel spins.
Since going back to the drawing board, there hasn't been really anything to report on KDBUS. In fact, there's no longer any current KDBUS code via GregKH's repository and the systemd KDBUS branches haven't been touched since Linux 4.3. I haven't been able to find any more recent KDBUS Git repository yet with the redesign.
Meanwhile, there's still the not yet officially released new "BUS1" in-kernel IPC mechanism that seems to share the same goals with KDBUS. The BUS1 Git repositories continue to be very active with the most recent commits being from today. Soon as there's new information to pass along on BUS1, you can expect to read more about it on Phoronix.