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/development/nim-packages/spryvm/nil.patch

@@ -0,0 +1,21 @@
+diff --git a/spryvm/spryui.nim b/spryvm/spryui.nim
+index 37f5329..50440e9 100644
+--- a/spryvm/spryui.nim
++++ b/spryvm/spryui.nim
+@@ -140,14 +140,14 @@ proc addUI*(spry: Interpreter) =
+   nimMeth("openFile"):
+     var win = WindowNode(evalArgInfix(spry))
+     var path = openFile(Window(win.widget))
+-    if path.isNil:
++    if path == "":
+       spry.nilVal
+     else:
+       newValue($path)
+   nimMeth("saveFile"):
+     var win = WindowNode(evalArgInfix(spry))
+     var path = saveFile(Window(win.widget))
+-    if path.isNil:
++    if path == "":
+       spry.nilVal
+     else:
+       newValue($path)