Removed constraint on mirror_spectrum fanout

The module name being used doesn't seem to be compatible with the latest FFT block.
Recompiled fine delay core

Changed multiplier latency to 4, to match the DSP cores being used.
Other values of multiplier latency won't work properly.
Lots of changes

This commit updates three models. simple_spec is a simple spectrometer,
with do delay compensation or phase rotation. No post-fft requantization.
Compiled at 250MHz FPGA clock (2GHz ADC)
ami_fx_sbl_wide is a two input correlator, with no post-fft requant.
Also at 2GHz ADC clock.
ami_fx_sbl is a 4bit single baseline correlator, compiled for (but not currently
working with the latest fft netlist) 312.5 MHz FPGA clock (2.5GHz ADC clock)