[nRF52840] add missing call to PlatformEventSignalPending in nRF52840 platform (#2348)
[nRF52840] add missing call to PlatformEventSignalPending in nRF52840 platform (#2348)


srickardti/openthread,erja-gp/openthread,jwhui/openthread,mszczodrak/openthread,pvanhorn/openthread,LeZhang2016/openthread,gandreello/openthread,turon/openthread,gandreello/openthread,chshu/openthread,georgecpr/openthread,turon/openthread,pvanhorn/openthread,xiaom-GitHub/openthread,srickardti/openthread,gandreello/openthread,srickardti/openthread,pvanhorn/openthread,bukepo/openthread,lanyuwen/openthread,mszczodrak/openthread,openthread/openthread,erja-gp/openthread,jwhui/openthread,abtink/openthread,pvanhorn/openthread,pvanhorn/openthread,xiaom-GitHub/openthread,abtink/openthread,chshu/openthread,abtink/openthread,gandreello/openthread,mszczodrak/openthread,lanyuwen/openthread,mszczodrak/openthread,LeZhang2016/openthread,erja-gp/openthread,LeZhang2016/openthread,xiaom-GitHub/openthread,librasungirl/openthread,georgecpr/openthread,chshu/openthread,lanyuwen/openthread,librasungirl/openthread,gandreello/openthread,xiaom-GitHub/openthread,lanyuwen/openthread,chshu/openthread,turon/openthread,bukepo/openthread,LeZhang2016/openthread,mszczodrak/openthread,jwhui/openthread,erja-gp/openthread,georgecpr/openthread,turon/openthread,georgecpr/openthread,openthread/openthread,georgecpr/openthread,erja-gp/openthread,LeZhang2016/openthread,bukepo/openthread,LeZhang2016/openthread,librasungirl/openthread,lanyuwen/openthread,openthread/openthread,librasungirl/openthread,pvanhorn/openthread,abtink/openthread,lanyuwen/openthread,xiaom-GitHub/openthread,srickardti/openthread,chshu/openthread,chshu/openthread,mszczodrak/openthread,gandreello/openthread,bukepo/openthread,erja-gp/openthread,openthread/openthread,jwhui/openthread,georgecpr/openthread,xiaom-GitHub/openthread