drm/amdgpu: Fix page table setup on Arcturus

When translate_further is enabled, page table depth needs to
be updated. This was missing on Arcturus MMHUB init. This was
causing address translations to fail for SDMA user-mode queues.

Fixes: 352e683b ("drm/amdgpu: Enable translate_further to extend UTCL2 reach")
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>