I have the same issue:
panic(cpu 4 caller 0xffffff800d0db75d): AMDFramebufferVIB::setPowerState(0xffffff9532b0d800 : 0xffffff7fa1cd58fc, 0 -> 1) timed out after 45639 ms @IOServicePM.cpp:5607
Panicked task 0xffffff86cd9d8870: 299 threads: pid 0: kernel_task
Backtrace (CPU 4), panicked thread: 0xffffff8b9b5f45a0, Frame : Return Address