PC5-U - passing (source,destination) down to PDCP/RLC/MAC (first alternative - mapping of L2Ids form IP Addresses

Seemed to have fixed pnf(UE) -vnf(eNB) sync issue. Works up to the reception of RRConnectionReconfigurationComplete message at the eNB but crashing after that.

fixes after merge with develop. Partial UE/eNB separation in build to avoid problems with NFAPI in oaisim UE/RRU.
tested with simulator.

Fix #582, RTAI, RTAI_ENABLED, ENABLE_RTAI_CLOCK, RTAI_ISNT_POSIX, _RTAI_MATH_H, CELLULAR, TIMER_ONESHOT_MODE, EMOS, EMOS_CHANNEL, OAI_EMU, OPENAIR_EMU, PHY_ABSTRACTION, PHY_ABSTRACTION_UL removed

Testing works up to the reception of SIB1/2/3 from the UE through nfapi, but there is an issue with missing some of the nfapi messages for some frames.

update SidelinkUEInformation (UE's side), RRCConnectionReconfiguration (eNB's side), add rrc_ue_process_radioResourceConfig to process RPs and configure MAC/PHY

phy_init_lte_ue_signal was renamed init_lte_ue_signal in openair1/PHY/INIT/defs.h
maybe it's the opposite that should have been done?

Functions used in one file and defined in another may have been
declared in the wrong header file.

Note: this commit is work in progress. Contains initial integration of NFAPI data structures which are tested for TX path. RX path to follow.

those popped up thanks to previous commit