[rocm-libraries] ROCm/rocm-libraries#8531 (commit 6851169)

[CK_TILE] Use launched block size for GEMM occupancy query
 (#8531)

The grouped, grouped-quant, and stream-k GEMM kernels were asking the
occupancy query about `kBlockSize`, but on wave32 (gfx1250) we actually
launch `kBlockSize/2`. So the occupancy came back too low and the
persistent/stream-k grid ended up undersized.

Just pass `BlockSize().x` like the universal and flatmm kernels already
do. No-op on wave64.

Verified it builds + runs correctly on gfx1250 (grouped gemm) and builds
on gfx950 (stream-k).