lms: add device type detection and device specific gains

add device dependant max gain setup - limesdr mini and limenet micro need slightly reduced maximum gains to get a PASS on phase error measurements
rework clock reference setup - external clock needs to be selected before calling LMS_Init(), internal can only be set after.
remove now unused compat_LMS_VCTCXO* functions - we do not set the VCTXCO directly anymore

Change-Id: I3cf905b0a84bc1ec200891762a6646141ee37181
3 files changed