drm/amdgpu: correct IH_CHICKEN programming for aldebaran

For aldebaran, psp firmware won't program IH_CHICKEN.
it now depends on driver to program it properly so
either bus address or gpu virtual address is just
working for ih ring.

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Dennis Li <Dennis.Li@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>