Added lvv-vivado

[berkgokmen14]

No description provided.

[matth2k]

So basically here are my changes:

1. I combined lvv and lvv-xilinx you made, since the Makefile is mostly shared code
2. If you run lvv with a different Makefile vxil recipe it uses Vivado instead
3. You can set this makefile recipe with FSTEM variable
4. I updated setup.sh so it can be ran from any working directory
5. I updated the run.sh scripts at https://github.com/matth2k/synth-benchmarks/tree/main/verilog/iscas85 and https://github.com/matth2k/synth-benchmarks/tree/main/verilog/lgsynth91

@berkgokmen14 does this work for you?

cd ~/synth-benchmarks # Or where ever you have it
source ~/lut_synth/utils/setup.sh
which lvv
cd verilog/iscas85
./run.sh # runs 8 jobs in parallel

If that works for, you I'll merge this PR.