qemu-riscv: remove, obsolete with qemu 2.12

upstream qemu 2.12 includes riscv support

pkgs/applications/virtualization/qemu/riscv.nix

@@ -1,30 +0,0 @@
-{ qemu, fetchFromGitHub, lib }: let
-  src = fetchFromGitHub {
-    owner  = "riscv";
-    repo   = "riscv-qemu";
-    rev    = "f733c7b5f86147216e14aff90c03ccdd76056bef";
-    sha256 = "1ppr9qqwi7qqh8m6dgk1hrzg8zri240il27l67vfayd8ijagb9zq";
-    fetchSubmodules = true;
-  };
-  version = "2.11.92";
-  revCount = "60378";
-  shortRev = builtins.substring 0 9 src.rev;
-  targets = [ "riscv32-linux-user" "riscv32-softmmu"
-              "riscv64-linux-user" "riscv64-softmmu"
-            ];
-in lib.overrideDerivation qemu (orig: {
-  name = "${(builtins.parseDrvName qemu.name).name}-${version}pre${revCount}_${shortRev}";
-  inherit src;
-# <<<<<<< HEAD
-#   # https://github.com/riscv/riscv-qemu/pull/109
-#   patches = [ ./no-etc-install.patch ./statfs-flags.patch ./riscv-initrd.patch ];
-# =======
-  # The pulseaudio and statfs patches are in 2.12.0+, which this is based on
-  patches = [
-    ./force-uid0-on-9p.patch
-    ./no-etc-install.patch
-  ];
-
-  configureFlags = orig.configureFlags ++ [ "--target-list=${lib.concatStringsSep "," targets}" ];
-  postInstall = null;
-})

pkgs/top-level/all-packages.nix

@@ -17424,8 +17424,6 @@ with pkgs;
     inherit (darwin.stubs) rez setfile;
   };
 
-  qemu-riscv = lowPrio (callPackage ../applications/virtualization/qemu/riscv.nix {});
-
   qgis = callPackage ../applications/gis/qgis {
     inherit (darwin.apple_sdk.frameworks) IOKit ApplicationServices;
   };