hipCUB beta hipclang 3.2.0

HipCUB changes to support multiple ROCM installation (#68)

- New mode of building is added "-r,--relocatable" which is used
  for ROCm stack installed in /opt/rocm-ver.
- Below CMAKE parameters are set/overwritten in above mode
  CMAKE_INSTALL_PREFIX
  CMAKE_PREFIX_PATH
  CMAKE_MODULE_PATH

Signed-off-by: Pruthvi Madugundu <[email protected]>

Co-authored-by: mpruthvikumar <[email protected]>