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/libraries/swiften/scons.patch

@@ -0,0 +1,9 @@
+--- a/BuildTools/SCons/SConscript.boot
++++ b/BuildTools/SCons/SConscript.boot
+@@ -129,5 +129 @@ vars.Add(PathVariable("sparkle_public_dsa_key", "Optional path to a public DSA k
+-env_ENV = {
+-    'PATH' : os.environ['PATH'],
+-    'LD_LIBRARY_PATH' : os.environ.get("LD_LIBRARY_PATH", ""),
+-    'TERM' : os.environ.get("TERM", ""),
+-}
++env_ENV = os.environ