drm/amdgpu: add PSP SW init support for Arcturus

Add arcturus cases to psp init sewquence.

Signed-off-by: John Clements <john.clements@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>