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/filesystems/mkspiffs/presets.nix

@@ -0,0 +1,20 @@
+{ lib, mkspiffs }:
+
+# We provide the same presets as the upstream
+
+lib.mapAttrs (
+  name: { CPPFLAGS }:
+  mkspiffs.overrideAttrs (drv: {
+    inherit CPPFLAGS;
+    BUILD_CONFIG_NAME = "-${name}";
+  })
+) {
+  arduino-esp8266.CPPFLAGS = [
+    "-DSPIFFS_USE_MAGIC_LENGTH=0"
+    "-DSPIFFS_ALIGNED_OBJECT_INDEX_TABLES=1"
+  ];
+
+  arduino-esp32.CPPFLAGS = [ "-DSPIFFS_OBJ_META_LEN=4" ];
+
+  esp-idf.CPPFLAGS = [ "-DSPIFFS_OBJ_META_LEN=4" ];
+}