Fix DMA critical warnings in Vivado 2021.1
After the switch to Vivado 2021.1 we see the following warnings during implementation:
CRITICAL WARNING: [Vivado_Tcl 4-907] Required Username value could not be determined from either the $USER environment variable or the -user optional switch. Please set username using one or other method; type 'create_waiver -help' for usage info. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/proj/scouting_build/scouting_build/scouting_build.gen/sources_1/ip/xdma_0/ip_0/source/xdma_0_pcie3_ip-PCIE_X0Y0.xdc:271]
CRITICAL WARNING: [Common 17-55] 'set_property' expects at least one object. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:1]
CRITICAL WARNING: [Common 17-55] 'set_property' expects at least one object. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:2]
CRITICAL WARNING: [Common 17-55] 'set_property' expects at least one object. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:3]
CRITICAL WARNING: [Common 17-55] 'set_property' expects at least one object. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:4]
CRITICAL WARNING: [Common 17-55] 'set_property' expects at least one object. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:136]
CRITICAL WARNING: [Vivado 12-4739] set_false_path:No valid object(s) found for '-from [get_clocks -of_objects [get_pins dma_engine_i/xdma_0_i/inst/pcie3_ip_i/U0/gt_top_i/phy_clk_i/bufg_gt_userclk/O]]'. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:152]
CRITICAL WARNING: [Vivado 12-4739] set_false_path:No valid object(s) found for '-to [get_clocks -of_objects [get_pins dma_engine_i/xdma_0_i/inst/pcie3_ip_i/U0/gt_top_i/phy_clk_i/bufg_gt_userclk/O]]'. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:153]
CRITICAL WARNING: [Vivado 12-4739] set_false_path:No valid object(s) found for '-to [get_clocks -of_objects [get_pins dma_engine_i/xdma_0_i/inst/pcie3_ip_i/U0/gt_top_i/phy_clk_i/bufg_gt_userclk/O]]'. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:154]
CRITICAL WARNING: [Vivado 12-4739] set_false_path:No valid object(s) found for '-from [get_clocks -of_objects [get_pins dma_engine_i/xdma_0_i/inst/pcie3_ip_i/U0/gt_top_i/phy_clk_i/bufg_gt_userclk/O]]'. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:155]
CRITICAL WARNING: [Vivado 12-4739] set_false_path:No valid object(s) found for '-from [get_clocks -of_objects [get_pins dma_engine_i/xdma_0_i/inst/pcie3_ip_i/U0/gt_top_i/phy_clk_i/bufg_gt_userclk/O]]'. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:157]
CRITICAL WARNING: [Vivado 12-4739] set_false_path:No valid object(s) found for '-to [get_clocks -of_objects [get_pins dma_engine_i/xdma_0_i/inst/pcie3_ip_i/U0/gt_top_i/phy_clk_i/bufg_gt_userclk/O]]'. [/builds/scouting-demonstrator/scouting-preprocessor/build/scouting/src/scouting-preprocessor/scouting-board/firmware/cfg/xilinx_pcie_xdma_ref_board.xdc:158]
This may be due to some changes in the DMA core.
Edited by Dinyar Rabady