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/cpu/intel-sgx.nix

@@ -0,0 +1,69 @@
+{ config, lib, ... }:
+with lib;
+let
+  cfg = config.hardware.cpu.intel.sgx;
+  defaultPrvGroup = "sgx_prv";
+in
+{
+  options.hardware.cpu.intel.sgx.enableDcapCompat = mkOption {
+    description = ''
+      Whether to enable backward compatibility for SGX software build for the
+      out-of-tree Intel SGX DCAP driver.
+
+      Creates symbolic links for the SGX devices <literal>/dev/sgx_enclave</literal>
+      and <literal>/dev/sgx_provision</literal> to make them available as
+      <literal>/dev/sgx/enclave</literal>  and <literal>/dev/sgx/provision</literal>,
+      respectively.
+    '';
+    type = types.bool;
+    default = true;
+  };
+
+  options.hardware.cpu.intel.sgx.provision = {
+    enable = mkEnableOption "access to the Intel SGX provisioning device";
+    user = mkOption {
+      description = "Owner to assign to the SGX provisioning device.";
+      type = types.str;
+      default = "root";
+    };
+    group = mkOption {
+      description = "Group to assign to the SGX provisioning device.";
+      type = types.str;
+      default = defaultPrvGroup;
+    };
+    mode = mkOption {
+      description = "Mode to set for the SGX provisioning device.";
+      type = types.str;
+      default = "0660";
+    };
+  };
+
+  config = mkMerge [
+    (mkIf cfg.provision.enable {
+      assertions = [
+        {
+          assertion = hasAttr cfg.provision.user config.users.users;
+          message = "Given user does not exist";
+        }
+        {
+          assertion = (cfg.provision.group == defaultPrvGroup) || (hasAttr cfg.provision.group config.users.groups);
+          message = "Given group does not exist";
+        }
+      ];
+
+      users.groups = optionalAttrs (cfg.provision.group == defaultPrvGroup) {
+        "${cfg.provision.group}" = { };
+      };
+
+      services.udev.extraRules = with cfg.provision; ''
+        SUBSYSTEM=="misc", KERNEL=="sgx_provision", OWNER="${user}", GROUP="${group}", MODE="${mode}"
+      '';
+    })
+    (mkIf cfg.enableDcapCompat {
+      services.udev.extraRules = ''
+        SUBSYSTEM=="misc", KERNEL=="sgx_enclave",   SYMLINK+="sgx/enclave"
+        SUBSYSTEM=="misc", KERNEL=="sgx_provision", SYMLINK+="sgx/provision"
+      '';
+    })
+  ];
+}