amarisoft_ue: Implement data plane

Use the ifup script to set up the netns + configure the tun device
created by lteue. Use it also as a hook to know when the UE is attached.
Since tun setup is done by arch-optimized lte-avx(2) binaries, we also
need to give capabilitites to them (instead of allowing inheritance of
caps in general in the setcap script).

Change-Id: I1e228b1296eac8e4cb183c2faa735b0468abe124
3 files changed