uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/modules/services/security/yubikey-agent.nix

@@ -0,0 +1,66 @@
+# Global configuration for yubikey-agent.
+
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.yubikey-agent;
+
+  # reuse the pinentryFlavor option from the gnupg module
+  pinentryFlavor = config.programs.gnupg.agent.pinentryFlavor;
+in
+{
+  ###### interface
+
+  meta.maintainers = with maintainers; [ philandstuff rawkode jwoudenberg ];
+
+  options = {
+
+    services.yubikey-agent = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to start yubikey-agent when you log in.  Also sets
+          SSH_AUTH_SOCK to point at yubikey-agent.
+
+          Note that yubikey-agent will use whatever pinentry is
+          specified in programs.gnupg.agent.pinentryFlavor.
+        '';
+      };
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.yubikey-agent;
+        defaultText = literalExpression "pkgs.yubikey-agent";
+        description = ''
+          The package used for the yubikey-agent daemon.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [ cfg.package ];
+    systemd.packages = [ cfg.package ];
+
+    # This overrides the systemd user unit shipped with the
+    # yubikey-agent package
+    systemd.user.services.yubikey-agent = mkIf (pinentryFlavor != null) {
+      path = [ pkgs.pinentry.${pinentryFlavor} ];
+      wantedBy = [
+        (if pinentryFlavor == "tty" || pinentryFlavor == "curses" then
+          "default.target"
+        else
+          "graphical-session.target")
+      ];
+    };
+
+    environment.extraInit = ''
+      if [ -z "$SSH_AUTH_SOCK" -a -n "$XDG_RUNTIME_DIR" ]; then
+        export SSH_AUTH_SOCK="$XDG_RUNTIME_DIR/yubikey-agent/yubikey-agent.sock"
+      fi
+    '';
+  };
+}