Special version for Trasmitter for the 7150 GSI 3x3 system

stx7150_GSI3x3_0401.bin

Revision register should read 0401

this is for the rev ("C"?) of the board that uses Single Ended LVCMOS FPGA outputs for the FET switches

This has tx fault circuits and the fault led's implemented.

This code works for 12kHz and 24kHz (which is selected by slot on the rack
in same way as other 7150 Transmitter subsystems)

This is based on the released 7150 code for all modules excpect the pulsewidth modulation module (ifpwm.v)
which is based the version done by Zeuxion and has the DC balance, and precharge fix.

Parametes are modified to account for the difference in the total number of channels (compared to dual rack 7150)

There are slight differences in the steering calculation in order to 
accomodate for the pivot point correctly
