Sorry for the late reply, yeah as @dos say you need new kernel plus new librem5-base packages to get it work, i think may be this 2 packages will be available to byzantium very soon.
Also i want to clarify something about Suspend to Ram and modem on my test, the Screen turn ON on the first dial-tone of the Call but is not Ring because Phosh still getting ready to start ringing, so the L5 start ring from suspend on the third dial-tone of the Caller.