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/text/uni2ascii/default.nix

@@ -0,0 +1,41 @@
+{ lib, stdenv, fetchurl }:
+
+stdenv.mkDerivation rec {
+  pname = "uni2ascii";
+  version = "4.18";
+
+  src = fetchurl {
+    url = "https://billposer.org/Software/Downloads/uni2ascii-${version}.tar.gz";
+    sha256 = "03lklnzr6ngs4wqiqa7rifd246f441gfvardbsaa5l6fn9pbn94y";
+  };
+
+  meta = {
+    license = lib.licenses.gpl3;
+    homepage = "http://billposer.org/Software/uni2ascii.html";
+    description = "Converts between UTF-8 and many 7-bit ASCII equivalents and back";
+
+    longDescription = ''
+    This package provides conversion in both directions between UTF-8
+    Unicode and more than thirty 7-bit ASCII equivalents, including
+    RFC 2396 URI format and RFC 2045 Quoted Printable format, the
+    representations used in HTML, SGML, XML, OOXML, the Unicode
+    standard, Rich Text Format, POSIX portable charmaps, POSIX locale
+    specifications, and Apache log files, and the escapes used for
+    including Unicode in Ada, C, Common Lisp, Java, Pascal, Perl,
+    Postscript, Python, Scheme, and Tcl.
+
+    Such ASCII equivalents are useful when including Unicode text in
+    program source, when debugging, and when entering text into web
+    programs that can handle the Unicode character set but are not
+    8-bit safe. For example, MovableType, the blog software, truncates
+    posts as soon as it encounters a byte with the high bit
+    set. However, if Unicode is entered in the form of HTML numeric
+    character entities, Movable Type will not garble the post.
+
+    It also provides ways of converting non-ASCII characters to
+    similar ASCII characters, e.g. by stripping diacritics.
+    '';
+    maintainers = with lib.maintainers; [ goibhniu ];
+    platforms = lib.platforms.all;
+  };
+}