N/A
Signed-off-by: NLuxuhui <luxuhui@xiaomi.com>

1. Move all files in kernels to ops
2. unify the op_def_registry and op_registry.
3. Support op clip: do not link the ops' code when the op is not registered.

1. Merge the Operation and OpKernel into Operation.
2. Add OpDefRegistry for registering the definitions of Operations.
3. Add information for MaceStatus.
4. Unify 'BatchNorm' and 'FoldedBatchNorm' into 'BatchNorm'
5. Remove unused op 'Proposal'