### What this PR does / why we need it?
We only do restore and recover for pcp, so we should set
`kv_inverse_idx_for_chunk` and `cp_kv_recover_idx_for_chunk` to `None`
when only using dcp.
- vLLM version: v0.14.1
- vLLM main:
dc917cceb8
Signed-off-by: QiuChunshuo <qiuchunshuo@huawei.com>