drm/amdgpu: Add Support for enforcing isolation without Cleaner Shader

Adjusted the enforce isolation setting handling to include the ability
to disable the cleaner shader without affecting isolation between tasks.

v2: Updated enforce isolation documentation and parameters. (Alex)

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>