fix largeK correctness issue
fix largeK correctness issue

1. non-power-of-2 GSU
  non-power-2 of GSU need divide operation.
  LargeK will make salu divide overflow
  use valu to handle non-power-2 of GSU case.

2. set buffer limit to ffffffff

ROCmSoftwarePlatform/Tensile,ROCmSoftwarePlatform/Tensile,ROCmSoftwarePlatform/Tensile