[travis] add link raw to nrf52840 build checks (#2875)
[travis] add link raw to nrf52840 build checks (#2875)


LeZhang2016/openthread,jwhui/openthread,lanyuwen/openthread,librasungirl/openthread,abtink/openthread,srickardti/openthread,lanyuwen/openthread,abtink/openthread,gandreello/openthread,erja-gp/openthread,LeZhang2016/openthread,erja-gp/openthread,bukepo/openthread,LeZhang2016/openthread,jwhui/openthread,jwhui/openthread,jwhui/openthread,turon/openthread,gandreello/openthread,bukepo/openthread,srickardti/openthread,chshu/openthread,abtink/openthread,librasungirl/openthread,librasungirl/openthread,openthread/openthread,erja-gp/openthread,librasungirl/openthread,srickardti/openthread,lanyuwen/openthread,openthread/openthread,erja-gp/openthread,chshu/openthread,lanyuwen/openthread,gandreello/openthread,chshu/openthread,bukepo/openthread,lanyuwen/openthread,openthread/openthread,chshu/openthread,turon/openthread,turon/openthread,LeZhang2016/openthread,gandreello/openthread,erja-gp/openthread,chshu/openthread,erja-gp/openthread,LeZhang2016/openthread,srickardti/openthread,turon/openthread,LeZhang2016/openthread,bukepo/openthread,chshu/openthread,abtink/openthread,openthread/openthread,lanyuwen/openthread,gandreello/openthread,gandreello/openthread