eal/windows: add minimum viable code

Add Windows specific logic for eal.c, eal_lcore.c,
eal_debug.c and eal_thread.c. Updated header files to
contain suitable function declarations.

Signed-off-by: Anand Rawat <anand.rawat@intel.com>
Signed-off-by: Pallavi Kadam <pallavi.kadam@intel.com>
Reviewed-by: Jeff Shaw <jeffrey.b.shaw@intel.com>
Reviewed-by: Ranjit Menon <ranjit.menon@intel.com>
Acked-by: Harini Ramakrishnan <harini.ramakrishnan@microsoft.com>