fixed compilation of bscan, but still has vivado placement problem

Change-Id: I709374cdce02b363e6de024c4db80b11bf1c643c
use underscore as a separator instead of dollar signs because verilog removes dollar signs

Change-Id: I6f5f523a98ec1549ed007c2bcd9fa281be71f600
corresponding CLOCK_DECL/CLOCK_ARG for bsv/Zc706.bsv

Change-Id: I6987fccc3657efa1ce41437ff0734a3c6541eb28
ignore generated ac701 directory

Change-Id: Ifcc4058e3ca60867ad9dbfe7448ebd0b6d5555bc