Reorder includes to prefer platform routines. Remove redundant RPL define.
Reorder includes to prefer platform routines. Remove redundant RPL define.

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