adding API for USRP function issue_stream_cmd so that we can do timed reads in the nr-ru. This functionality is only enabled using a new flag use_single_antenna_port_for_tdd in openair0_cfg

this flaf will also put TX and RX on the same TRX antenna port

further usrp time now synchronized on pps, even when not using gps

Nr rrc configuration

See merge request oai/openairinterface5g!738

inline alone does only define a function without a corresponding
declaration. static solves this problem

rfsim works

an assertion fails in gnb (need to be fixed)

Merge branch 'NR_RRCConfiguration' of https://gitlab.eurecom.fr/oai/openairinterface5g into NR_RRCConfiguration

temporary changes for nr_ulsim. To be removed when new branch with SCF NR FAPI for PUSCH is merged in.

Develop integration 2020 week 11

See merge request oai/openairinterface5g!787

Merge branch 'NR_RRCConfiguration' of https://gitlab.eurecom.fr/oai/openairinterface5g into NR_RRCConfiguration

Conflicts:
	executables/nr-softmodem.c
	executables/nr-ue.c
	executables/softmodem-common.c
	openair1/PHY/NR_TRANSPORT/nr_ulsch_decoding.c
	openair1/SCHED_NR/phy_procedures_nr_gNB.c
	openair1/SIMULATION/NR_PHY/dlsim.c
	openair1/SIMULATION/NR_PHY/ulsim.c
	openair2/LAYER2/NR_MAC_UE/mac_proto.h
	openair2/NR_PHY_INTERFACE/NR_IF_Module.c
	openair2/RRC/NR/MESSAGES/asn1_msg.c
	openair2/RRC/NR/MESSAGES/asn1_msg.h
	openair2/RRC/NR/nr_rrc_config.c
	openair2/RRC/NR/nr_rrc_defs.h
	openair2/RRC/NR/nr_rrc_proto.h
	openair2/RRC/NR/rrc_gNB.c

Fix for Issue #494: check and handle return value of openair0_device_load()  (develop branch)

See merge request oai/openairinterface5g!780

Fix l2 sim

See merge request oai/openairinterface5g!781