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>

pkgs/tools/security/certmgr/default.nix

@@ -0,0 +1,43 @@
+{ lib, buildGoPackage, fetchFromGitHub, fetchpatch }:
+
+let
+  generic = { patches ? [] }:
+    buildGoPackage rec {
+      version = "1.6.4";
+      pname = "certmgr";
+
+      goPackagePath = "github.com/cloudflare/certmgr/";
+
+      src = fetchFromGitHub {
+        owner = "cloudflare";
+        repo = "certmgr";
+        rev = "v${version}";
+        sha256 = "0glvyp61ya21pdm2bsvq3vfhmmxc2998vxc6hiyc79ijsv9n6jqi";
+      };
+
+      inherit patches;
+
+      meta = with lib; {
+        homepage = "https://cfssl.org/";
+        description = "Cloudflare's certificate manager";
+        platforms = platforms.linux;
+        license = licenses.bsd2;
+        maintainers = with maintainers; [ johanot srhb ];
+      };
+    };
+in
+{
+  certmgr = generic {};
+
+  certmgr-selfsigned = generic {
+    # The following patch makes it possible to use a self-signed x509 cert
+    # for the cfssl apiserver.
+    # TODO: remove patch when PR is merged.
+    patches = [
+      (fetchpatch {
+        url    = "https://github.com/cloudflare/certmgr/pull/51.patch";
+        sha256 = "0jhsw159d2mgybvbbn6pmvj4yqr5cwcal5fjwkcn9m4f4zlb6qrs";
+      })
+    ];
+  };
+}