Modernize CMake

[e-kwsm]

At the moment the minimum required version of CMake is set to 2.8, which is quite old.

scalapack/CMakeLists.txt

Line 1 in 6c76aaa

cmake_minimum_required(VERSION 2.8)

CMake 3.20.2 raises the following warning:

CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 2.8.12 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.