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/nettle/cygwin.patch

@@ -0,0 +1,12 @@
+Cygwin sucks.  Patch suggested by Niel Möller.
+
+--- nettle-2.0/examples/setup-env	2009-06-08 20:27:12.000000000 +0200
++++ nettle-2.0/examples/setup-env	2009-09-18 16:58:03.000000000 +0200
+@@ -3,5 +3,5 @@
+ set -e
+ 
+ if [ -x rsa-keygen ] ; then
+-  ./rsa-keygen -r rsa-decrypt -o testkey || exit 1
++  ./rsa-keygen -r rsa-decrypt.exe -o testkey || exit 1
+ fi
+