libraries: Removes unneeded cmake_minimum_required(VERSION 2.6)

The minimum required cmake version is already set in the root CMakeLists.

Signed-off-by: Luís Pereira <luis.artur.pereira@gmail.com>
libraries: Removes unneeded include(RazorLibSuffix)

RazorLibSuffix is included in the root CMakeLists.

Signed-off-by: Luís Pereira <luis.artur.pereira@gmail.com>