[nrf52840] do not include libjlinkrtt in the SDK version of OT libs (#3445)
[nrf52840] do not include libjlinkrtt in the SDK version of OT libs (#3445)

Signed-off-by: Szkotak, Piotr <3f40624111b9ceae48d60f16fc6805f2b3d0a1f0@nordicsemi.no>
librasungirl/openthread,erja-gp/openthread,chshu/openthread,chshu/openthread,lanyuwen/openthread,openthread/openthread,jwhui/openthread,srickardti/openthread,turon/openthread,lanyuwen/openthread,jwhui/openthread,lanyuwen/openthread,jwhui/openthread,bukepo/openthread,chshu/openthread,librasungirl/openthread,openthread/openthread,erja-gp/openthread,jwhui/openthread,lanyuwen/openthread,librasungirl/openthread,chshu/openthread,abtink/openthread,librasungirl/openthread,lanyuwen/openthread,chshu/openthread,erja-gp/openthread,openthread/openthread,bukepo/openthread,abtink/openthread,bukepo/openthread,srickardti/openthread,turon/openthread,abtink/openthread,bukepo/openthread,erja-gp/openthread,lanyuwen/openthread,turon/openthread,srickardti/openthread,erja-gp/openthread,turon/openthread,chshu/openthread,srickardti/openthread,openthread/openthread,erja-gp/openthread,abtink/openthread