rocm-cmake is a collection of CMake modules for common build and development tasks within the ROCm project. It is therefore a build dependency for many of the libraries that comprise the ROCm platform.
rocm-cmake is not required for building libraries or programs that use ROCm; it is required for building some of the libraries that are a part of ROCm.
To install from source, run:
mkdir build
cd build
cmake ..
cmake --build .
sudo cmake --build . --target install