Fix test_cache_int32_overflow test failure on ROCm

[avbokovoy]

This PR introduces the fix for test_cache_int32_overflow test on ROCm. Currently, the test fails with the following error:

RuntimeError: Total number of threads 16384000000 is greater than the HIP limit of 2^32

The changes are:

1. Add an ability for lxu_cache_flush_cuda kernel to handle arbitrary sized grids with runtime max_grid_size scheduling
2. Fixed potential integer overflows
3. Added TORCH_CHECK to avoid potential division by zero