Includes Windows-specific EAL changes and meson changes to build the code on windows.
v7 Changes: 1. Fixed rte_os.h not found issue on linux and freebsd. 2. Fixed missing def issues on linux and freebsd. 3. Updated comments in header files to be more descriptive Acked-by: Harini Ramakrishnan <harini.ramakrish...@microsoft.com>
