drm/amdgpu: do RAS MCA2PA conversion in device init phase

NPS mode is introduced, the value of memory physical address (PA)
related to a MCA address varies per nps mode. We need to rely on
MCA address and convert it into PA accroding to nps mode.

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>