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/tests/adguardhome.nix

@@ -0,0 +1,57 @@
+import ./make-test-python.nix {
+  name = "adguardhome";
+
+  nodes = {
+    minimalConf = { ... }: {
+      services.adguardhome = { enable = true; };
+    };
+
+    declarativeConf = { ... }: {
+      services.adguardhome = {
+        enable = true;
+
+        mutableSettings = false;
+        settings = {
+          dns = {
+            bind_host = "0.0.0.0";
+            bootstrap_dns = "127.0.0.1";
+          };
+        };
+      };
+    };
+
+    mixedConf = { ... }: {
+      services.adguardhome = {
+        enable = true;
+
+        mutableSettings = true;
+        settings = {
+          dns = {
+            bind_host = "0.0.0.0";
+            bootstrap_dns = "127.0.0.1";
+          };
+        };
+      };
+    };
+  };
+
+  testScript = ''
+    with subtest("Minimal config test"):
+        minimalConf.wait_for_unit("adguardhome.service")
+        minimalConf.wait_for_open_port(3000)
+
+    with subtest("Declarative config test, DNS will be reachable"):
+        declarativeConf.wait_for_unit("adguardhome.service")
+        declarativeConf.wait_for_open_port(53)
+        declarativeConf.wait_for_open_port(3000)
+
+    with subtest("Mixed config test, check whether merging works"):
+        mixedConf.wait_for_unit("adguardhome.service")
+        mixedConf.wait_for_open_port(53)
+        mixedConf.wait_for_open_port(3000)
+        # Test whether merging works properly, even if nothing is changed
+        mixedConf.systemctl("restart adguardhome.service")
+        mixedConf.wait_for_unit("adguardhome.service")
+        mixedConf.wait_for_open_port(3000)
+  '';
+}