Clearify build instructions

[tpkessler]

I'm trying to build rocprofiler under Arch Linux from source. The build instructions in the README state

- ROCm is required.

Could you please specify which parts of ROCm are needed? I'm confused since rocprofiler itself is part of ROCM: https://github.com/RadeonOpenCompute/ROCm#rocm-binary-package-structure

[eshcherb]

I have updated th README as:

• ROCm is required. ROCr-runtime and roctracer are needed

https://github.com/ROCm-Developer-Tools/rocprofiler#to-build-with-the-current-installed-rocm

[tpkessler]

Thank you @eshcherb. This matches the dependencies I found by looking into the CMakeLists.txt and trial and error.