drm/amdgpu: Add WARN_ON to the resource clear function

Set the dirty bit when the memory resource is not cleared
during BO release.

v2(Christian):
  - Drop the cleared flag set to false.
  - Improve the amdgpu_vram_mgr_set_clear_state() function.

v3:
  - Add back the resource clear flag set function call after
    being cleared during eviction (Christian).
  - Modified the patch subject name.

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>