Include dummies for posix functions missing in cc65 C-library.
Include dummies for posix functions missing in cc65 C-library.

arurke/contiki,arurke/contiki,bluerover/6lbr,bluerover/6lbr,MohamedSeliem/contiki,arurke/contiki,arurke/contiki,arurke/contiki,MohamedSeliem/contiki,arurke/contiki,MohamedSeliem/contiki,bluerover/6lbr,bluerover/6lbr,MohamedSeliem/contiki,MohamedSeliem/contiki,bluerover/6lbr,bluerover/6lbr,bluerover/6lbr,MohamedSeliem/contiki,arurke/contiki,MohamedSeliem/contiki