drm/amdgpu: Update PTE flags with TF enabled

This patch updates the PTE flags when translate further (TF) is
enabled:
- With translate_further enabled, invalid PTEs can be 0. Reading
  consecutive invalid PTEs as 0 is considered a fault. To prevent
  this, ensure invalid PTEs have at least 1 bit set.
- The current invalid PTE flags settings to translate a retry fault
  into a no-retry fault, doesn't work with TF enabled. As a result,
  update invalid PTE flags settings which works for both TF enabled
  and disabled case.

Fixes: 352e683b

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