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/hardware/usb-wwan.nix

@@ -0,0 +1,39 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+  ###### interface
+
+  options = {
+
+    hardware.usbWwan = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable this option to support USB WWAN adapters.
+        '';
+      };
+    };
+  };
+
+  ###### implementation
+
+  config = mkIf config.hardware.usbWwan.enable {
+    # Attaches device specific handlers.
+    services.udev.packages = with pkgs; [ usb-modeswitch-data ];
+
+    # Triggered by udev, usb-modeswitch creates systemd services via a
+    # template unit in the usb-modeswitch package.
+    systemd.packages = with pkgs; [ usb-modeswitch ];
+
+    # The systemd service requires the usb-modeswitch-data. The
+    # usb-modeswitch package intends to discover this via the
+    # filesystem at /usr/share/usb_modeswitch, and merge it with user
+    # configuration in /etc/usb_modeswitch.d. Configuring the correct
+    # path in the package is difficult, as it would cause a cyclic
+    # dependency.
+    environment.etc."usb_modeswitch.d".source = "${pkgs.usb-modeswitch-data}/share/usb_modeswitch";
+  };
+}