drm/amdgpu: Remove duplicate fdinfo fields

Some of the fields that are handled by drm_show_fdinfo() crept back in
when rebasing the patch.  Remove them again.

Fixes: 376c25f8

 ("drm/amdgpu: Switch to fdinfo helper")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by:  <alexander.deucher@amd.com>
Co-developed-by: Umio Yasuno <coelacanth_dream@protonmail.com>
Signed-off-by: Umio Yasuno <coelacanth_dream@protonmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>