Comment # 12 on bug 92974 from charlie

Both patches ("disable_gen3.diff" and "fiji_disable_pcie_dpm.diff") applied
independently of each other work.  The kernel boots normally and X starts
normally.

These commands were issued before each *.diff was applied and compiled:
"git clean -dxf ; git fetch --all ; git reset --hard origin/amdgpu-powerplay"