clean up junks

test/Vivadofile

-#
-# Required options
-#
-
-# You may use SystemVerilog, Verilog, or VHDL files as sources.
-# sources=(test_main.sv lib/* ./mod?.v)
-sources=()
-
-# The directory where generated bitstream is put
-bit_dir=./build
-
-# All of your top_modules and its constraint files.
-# top_modules=(
-#     "test_main:constraint/test_main.xdc"
-#     "mod1:constraint/mod1.xdc"
-# )
-top_modules=(
-
-)
-
-# Your default top_module. Maybe override by commandline option.
-# top_module=test_main
-top_module=
-
-#
-# Optional options
-#
-
-# Path to vivado executable. It will override environment variable `vivado_exec`
-# vivado_exec="/path/to/vivado"
-
-# It's recommanded to set thread_num to cores of your CPU.
-# thread_num=4