[toolchain] define __COUNTER__ for keil compiler (#3545)
[toolchain] define __COUNTER__ for keil compiler (#3545)


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