NR 20 MHz with LTE raster on AW2S Jaguar.

Contains : changes to AW2S interface and OAI IF5 (openair1 and generic ethernet device), first set to support 2x2 NR 20 MHz on LTE raster using LTE ORI interfaces. Initial NR ORI (AW2S specific) interfaces are here, but new MR will come after testing with Panther 4x4 is complete. Also contains support for MIMO in SA (I was waiting for Francesco's MIMO branch in NSA to be merged) which was tested with AW2S Jaguar. Finally a few other things, minor changes to support 2.5 ms TDD periods in the configuration file. A programmable sl_ahead in the RU section allows for lowering latency on TX and RX. The default sl_ahead is still 6 (3ms @30kHz SCS), but can be reduced to 3 (1.5ms) or 4 (2 ms) on AW2S at least. A few other programmable parameters in MACRLC section: min_grant_prb (default 5) is the size of the minimum UL periodic grant in PRBs, min_grant_mcs (default is 9) is the MCS of the latter, harq_round_max is the limit on the HARQ rounds (1 means no HARQ, default is 4). um_on_default_drb in the top-level of configuration file selects RLC-UM instead of RLC-AM for the default bearer.