#16364: split prefetch dependent config

[nhuang-tt]

Split prefetch depends on up/downstream prefetcher

Ticket

#16364

Problem description

Dispatcher split_prefetch compile arg is hardcoded. It needs to be dynamic based on if the up/downstream prefetcher is HD or not. Some experimental cases like test_prefetcher needs this

What's changed

Move split_prefetch into dispatcher dependent_config_t

Checklist

TGG: https://github.com/tenstorrent/tt-metal/actions/runs/13131888170
All Post Commit: https://github.com/tenstorrent/tt-metal/actions/runs/13131884104
T3K: https://github.com/tenstorrent/tt-metal/actions/runs/13131891540/job/36638838359

• Post commit CI passes
• Blackhole Post commit (if applicable)
• Model regression CI testing passes (if applicable)
• Device performance regression CI testing passes (if applicable)
• (For models and ops writers) Full new models tests passes
• New/Existing tests provide coverage for changes