Revert "migen: add patch to limit vivado threads to 1"

This reverts commit 8f7308b036.

artiq-fast/pkgs/migen-limit-vivado-threads-to-1.patch

@@ -1,24 +0,0 @@
-From 59a61be1b7b7cb45f5494b980b9f37e2838d6e6a Mon Sep 17 00:00:00 2001
-From: Astro <astro@spaceboyz.net>
-Date: Wed, 10 Jun 2020 19:29:25 +0200
-Subject: [PATCH] limit vivado threads to 1
-
----
- migen/build/xilinx/vivado.py | 1 +
- 1 file changed, 1 insertion(+)
-
-diff --git a/migen/build/xilinx/vivado.py b/migen/build/xilinx/vivado.py
-index d2cf101..e9e4b77 100644
---- a/migen/build/xilinx/vivado.py
-+++ b/migen/build/xilinx/vivado.py
-@@ -149,6 +149,7 @@ class XilinxVivadoToolchain:
- 
-         # script that calls above steps
-         tcl = []
-+        tcl.append("set_param general.maxThreads 1")
-         tcl.append("source \"{}_route.tcl\"".format(build_name))
-         tcl.append("source \"{}_bitstream.tcl\"".format(build_name))
-         tools.write_to_file(build_name + ".tcl", "\n".join(tcl))
--- 
-2.26.2
-

artiq-fast/pkgs/python-deps.nix

@@ -86,11 +86,6 @@ rec {
       rev = "b1b2b298b85a795239daad84c75be073ddc4f8bd";
       sha256 = "1qy2ydk8xqqv92i992j1g71fbi185zd6s3kigzsf3169874dyh81";
     };
-    patches = [
-      # Vivado synthesis processes consume over 1 GB of RSS each. Limit them to
-      # 1 thread because they can become overwhelming during parallel builds.
-      ./migen-limit-vivado-threads-to-1.patch
-    ];
 
     propagatedBuildInputs = with python3Packages; [ colorama ];