drm/amd/powerplay: unify the prompts on thermal interrupts

The prompts will contain pci address(segment/bus/port/function),
severity(warn or error) and some keywords(GPU, amdgpu). Also this
address the issue that pci bus retrieved by PCI_BUS_NUM(adev->pdev->devfn)
is wrong.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>