treewide: use gnu toolchain for avr/arm-embedded

These packages should in theory work with our GCC toolchains, but
there are some definite breakages that need to be tracked down.
Comparing output of these to old gcc-arm-embedded is important.

Affected packages include:

- axolooti
- avrdudess
- opentx
- microscheme
- betaflight
- inav
- blackmagic
- simavr
- gnuk

pkgs/misc/gnuk/generic.nix

@@ -1,4 +1,4 @@
-{ stdenv, gcc-arm-embedded, makeWrapper
+{ stdenv, gcc-arm-embedded, binutils-arm-embedded, makeWrapper
 , python, pythonPackages
 
 # Extra options
@@ -14,7 +14,7 @@ stdenv.mkDerivation {
 
   inherit src;
 
-  nativeBuildInputs = [ gcc-arm-embedded makeWrapper ];
+  nativeBuildInputs = [ gcc-arm-embedded binutils-arm-embedded makeWrapper ];
   buildInputs = [ python ] ++ (with pythonPackages; [ pyusb colorama ]);
 
   configurePhase = ''