Kill duplication between l1_if.c and sysmbots_ctrl.c
The l1_if.c has working (with sanity) checks calibration code, the sysmobts_ctrl.c duplicates the code (but doesn't do the sanity checks). The CTRL interface code should interface to the code just like the VTY. This will lead to a consistent result.
To achieve this the l1_if routines could get a "callback" data structure that will be passed around.