Responding to myself but Raf Czlonka (@rjc) pointed out something that seems to be important.
Before @jcs azalia driver fixes for Matebook X were in repo I was building kernel from my local, patched sources. And recently, these changes were accepted and I started using snapshot kernel. And I think then suspend stopped working. I'm back to building kernel (no local changes this time) and problems are gone. -- Krystian
