Add Support for Xilinx KCU116 (#322)

* initial kcu116 support

* add kintex ultrascale plus family to xilinx.cpp

* add docs

* combine xcku and xcvu check

* rebuild bitstream for -1 speedgrade

doc/boards.yml

@@ -725,3 +725,10 @@
   FPGA: Virtex UltraScale+ xcvu37p-fsvh2892
   Memory: OK
   Flash: OK
+
+- ID: kcu116
+  Description: Xilinx KCU116
+  URL: https://www.xilinx.com/products/boards-and-kits/kcu116.html
+  FPGA: Kintex UltraScale+ xcku5p-ffvb676
+  Memory: OK
+  Flash: OK

doc/vendors/xilinx.rst

@@ -97,7 +97,7 @@ File load:
   device/package format is something like xc7a35tcsg324 (arty model).
   See :ghsrc:`src/board.hpp <src/board.hpp>`, or :ghsrc:`spiOverJtag <spiOverJtag>` directory for examples.
 
-Some boards with UltraScale FPGAs, like the VCU118, support the SPIx8 (Dual Quad SPI) configuration.
+Some boards with UltraScale FPGAs, like the VCU118 and KCU16, support the SPIx8 (Dual Quad SPI) configuration.
 In this case, the ``spix8`` option ``write_cfgmem`` on the above example can be used to generate two ``.mcs`` files,
 to fit bigger designs or for faster programming. Only ``.mcs`` files can be used to program the FPGA in this case.