Update/cleanup CMake for ROCM
Remove the custom FindROCM-SMI.cmake
helper. Instead, use the $ROCM_ROOT/lib/cmake
files to rocm_smi
and create a custom target ROCM::smi
with appropriate libraries and include directories configured. The PATH
hint /opt/rocm
is no longer there, so one may need to set CMAKE_PREFIX_PATH=$ROCM_ROOT
when BUILD_ROCM_PMT=1
.