AMDGPU-pro 18.50 opencl pal and legacy drivers are recognized as different platforms, but with Windows 19.3.2 adrenalin drivers and ROCm 2.2 drivers these cards are correctly assigned to one AMD platform. for the RX480 it uses the legacy drivers, and for Vega 56 it uses pal drivers.
pal.legacy.txt is the output of clinfo AMDGPU-pro 18.50 opencl pal and legacy drivers
win.txt is the output of clinfo in windows
rocm.txt is the output of clinfo with ROCm 2.2 drivers