### What this PR does / why we need it? Fix a bug for PD disaggregate of PCP/DCP, some conditions only consider MLA while ignoring DSA. ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? - vLLM version: v0.15.0 - vLLM main:15d76f74e2- vLLM Ascend main:81fb7d5779Signed-off-by: tongyuzhou <tongyuzhou1@huawei.com> Co-authored-by: tongyuzhou <tongyuzhou1@huawei.com>