hack: in schedule_ue_spec, 3 bytes are "reserved" (this should be
done better). An RLC AM entity may ask for only 2 bytes for
ACKing and get a TBS of 32 bits and due to these 3 reserved bytes we may
end up with only 1 byte left for RLC, which is not enough. This hack
prevents the problem. To be done better at some point. If the function
schedule_ue_spec is (has been) reworked, this hack can be removed.
Dig for "TBS - ta_len - header_length_total - sdu_length_total - 3"
in schedule_ue_spec.

This should be done better at some point.

Develop integration 2020 week 26

See merge request oai/openairinterface5g!841

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Merge remote-tracking branch 'origin/NR_RRC_X2AP_RemoveHardcodings_GlobalEdge' into develop_integration_2020_w26

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Conflicts:
	openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c

Develop integration 2020 week 25

The following Merge Requests have been included:

* MR 799 : NR RRC PRACH procedures
* MR 831 : NR PUCCH2 polar implementation
* MR 832 : coarse scope cleanup
* MR 835 : fix NR UE transport on PBCH
* MR 836 : NR fix phytest packet corruption DLSCH

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Merge remote-tracking branch 'origin/nr_fix_phytest_packet_corruption_dlsch' into develop_integration_2020_w25

- Payload was filled with zeros instead of random bytes

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>