Added inclusion of string header as required by gcc10
Added inclusion of string header as required by gcc10

Signed-off-by: Lowren Lawson <dffab2815f75df92cc8df158c2862035ecca479a@intel.com>

cmcantalupo/geopm,geopm/geopm,geopm/geopm,cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,geopm/geopm