fpga: lib: Add synthesizable AXI4-Stream SV components

Components are connected together with AxiStreamIfc. Some features
include:
  (1) Add bytes to the start of a packet
  (2) Remove bytes from a packet
  (3) Wrappers for some older components
      a.  fifo - buffer but imediately pass a packet
      b.  packet_gate - buffer and hold till end of packet
      c.  width_conv - cross clock domains and change width of axi bus

The AxiStreamIf was moved from PkgAxiStreamBfm to its own file. It can
be used to connect to ports with continuous assignment.
AxiStreamPacketIf must be used procedurally but allows the following
new methods:
  - reached_packet_byte - notify when tdata contains a paritcular byte
  - get_packet_byte/get_packet_field - extract a byte or field from axi
  - put_packet_byte/put_packet_field - overwrite a byte or field onto axi


Original-commit: c3bca6c87700054c96320de119a58f6a688dbd5a

lib/axi4s_sv/axi4s_remove_bytes_tb/Makefile

@@ -0,0 +1,48 @@
+#
+# Copyright 2020 Ettus Research, a National Instruments Brand
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+#
+
+#-------------------------------------------------
+# Top-of-Makefile
+#-------------------------------------------------
+# Define BASE_DIR to point to the "top" dir
+BASE_DIR = $(abspath ../../../top)
+# Include viv_sim_preamble after defining BASE_DIR
+include $(BASE_DIR)/../tools/make/viv_sim_preamble.mak
+
+#-------------------------------------------------
+# Design Specific
+#-------------------------------------------------
+
+# Include makefiles and sources for the DUT and its dependencies
+include $(BASE_DIR)/../lib/axi4s_sv/Makefile.srcs
+
+DESIGN_SRCS = $(abspath \
+$(AXI4S_SV_SRCS) \
+)
+
+#-------------------------------------------------
+# Testbench Specific
+#-------------------------------------------------
+# Define only one toplevel module
+TB_TOP_MODULE = axi4s_remove_bytes_all_tb
+SIM_TOP = $(TB_TOP_MODULE)
+
+SIM_SRCS = \
+$(abspath $(TB_TOP_MODULE).sv )\
+$(abspath axi4s_remove_bytes_tb.sv )
+
+# supressing the following worthless reminder.
+#* Warning: M:/usrp4-hw/oss-repo/fpga/usrp3/lib/axi4s_sv/axi4s_remove_bytes.sv(228): (vlog-2583) [SVCHK] -
+# Extra checking for conflicts with always_comb and always_latch variables is done at vopt time
+SVLOG_ARGS = -suppress 2583
+
+#-------------------------------------------------
+# Bottom-of-Makefile
+#-------------------------------------------------
+# Include all simulator specific makefiles here
+# Each should define a unique target to simulate
+# e.g. xsim, vsim, etc and a common "clean" target
+include $(BASE_DIR)/../tools/make/viv_simulator.mak