Fix alignment issue on ARM
Fix alignment issue on ARM

Signed-off-by: Maxim Osipov <3be22ebcf69784a7f74fbf51168974077a63c594@gmail.com>

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