[DONTMERGE] surfna example configuration

This uses a TWRP device tree generated using

 - https://github.com/SebaUbuntu/TWRP-device-tree-generator

And a known working recovery.img as a base.

Though it does not boot.

I guess one would need to investigate with other devices to have a
better understanding of why.

The recovery.img this produces has the same exact configuration and
files, according to unpackbootimg, except for os level, os version and
cmdline. Re-packing with those from the vendor recovery.img changed
nothing.

So, to recap, I have repacked from an unpackimg extraction BOTH this
TWRP and the stock recovery. The repacked stock recovery still works,
any TWRP will not.

The only difference is the ramdisk.

Author: samueldr

surfna-twrp.nix

@@ -0,0 +1,25 @@
+# SPDX-FileCopyrightText: 2021 Samuel Dionne-Riel
+# SPDX-FileCopyrightText: 2021 Daniel Fullmer and robotnix contributors
+# SPDX-License-Identifier: MIT
+
+#
+# Usage
+# =====
+#
+# ```
+# $ nix-build --arg configuration ./sofiar-twrp.nix -A config.build.twrp
+# ```
+#
+
+{ config, pkgs, lib, ... }:
+
+{
+  device = "surfna";
+  androidVersion = 9;
+  flavor = "twrp";
+  source.dirs = {
+    "device/motorola/surfna" = {
+      src = builtins.fetchGit ~/tmp/TWRP/android_device_motorola_surfna;
+    };
+  };
+}