Various bug fixes / enable subtile > 2

[drisspg]

Various bug fixes / enable subtile > 2

1. For small headdim we were expanding up to block_m 192. For the default block-q of 128. Update to take the block_sparse q size for both fwd and bwd.
2. added get_sparse_q_block_size this ideally just returns None if no sparsity or the set size from input. I am like 99% all things have been swapped to using the explicit setting of blocksparse data. We have switch over already in PT but want to give it 1 more release so we still infer just in case.
3. When enabling a viable 192, 128 -> noticed a kernel hang in the bwd. This was the first time we were hitting dQ_single_wg so I fixed to use the correct wg count
4. Also enabled subtiling > 2 which is the case for 192 block Q and m_tile 64 in thw bwd