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/config/power-management.nix

@@ -0,0 +1,106 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+
+  cfg = config.powerManagement;
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    powerManagement = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = true;
+        description =
+          ''
+            Whether to enable power management.  This includes support
+            for suspend-to-RAM and powersave features on laptops.
+          '';
+      };
+
+      resumeCommands = mkOption {
+        type = types.lines;
+        default = "";
+        description = "Commands executed after the system resumes from suspend-to-RAM.";
+      };
+
+      powerUpCommands = mkOption {
+        type = types.lines;
+        default = "";
+        example = literalExpression ''
+          "''${pkgs.hdparm}/sbin/hdparm -B 255 /dev/sda"
+        '';
+        description =
+          ''
+            Commands executed when the machine powers up.  That is,
+            they're executed both when the system first boots and when
+            it resumes from suspend or hibernation.
+          '';
+      };
+
+      powerDownCommands = mkOption {
+        type = types.lines;
+        default = "";
+        example = literalExpression ''
+          "''${pkgs.hdparm}/sbin/hdparm -B 255 /dev/sda"
+        '';
+        description =
+          ''
+            Commands executed when the machine powers down.  That is,
+            they're executed both when the system shuts down and when
+            it goes to suspend or hibernation.
+          '';
+      };
+
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    systemd.targets.post-resume = {
+      description = "Post-Resume Actions";
+      requires = [ "post-resume.service" ];
+      after = [ "post-resume.service" ];
+      wantedBy = [ "sleep.target" ];
+      unitConfig.StopWhenUnneeded = true;
+    };
+
+    # Service executed before suspending/hibernating.
+    systemd.services.pre-sleep =
+      { description = "Pre-Sleep Actions";
+        wantedBy = [ "sleep.target" ];
+        before = [ "sleep.target" ];
+        script =
+          ''
+            ${cfg.powerDownCommands}
+          '';
+        serviceConfig.Type = "oneshot";
+      };
+
+    systemd.services.post-resume =
+      { description = "Post-Resume Actions";
+        after = [ "suspend.target" "hibernate.target" "hybrid-sleep.target" ];
+        script =
+          ''
+            /run/current-system/systemd/bin/systemctl try-restart post-resume.target
+            ${cfg.resumeCommands}
+            ${cfg.powerUpCommands}
+          '';
+        serviceConfig.Type = "oneshot";
+      };
+
+  };
+
+}