drm/amdgpu: enable ih1 ih2 for Arcturus only

Enable multi-ring ih1 and ih2 for Arcturus only.
For Navi10 family multi-ring has been disabled.
Apparently, having multi-ring enabled in Navi was causing
continus page fault interrupts.
Further investigation is needed to get to the root cause.
Related issue link:
https://gitlab.freedesktop.org/drm/amd/-/issues/1279



Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>