added undef of putchar for platforms where it is a macro
added undef of putchar for platforms where it is a macro

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