drm/amdgpu: Mark debug KFD module params as unsafe

Mark options only meant to be used for debugging as unsafe so that the
kernel is tainted when they are used.

Signed-off-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>