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/development/compilers/microscheme/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchzip, vim, avrdude, avrbinutils, avrgcc, avrlibc, makeWrapper }:
+{ stdenv, fetchzip, vim, makeWrapper }:
 
 stdenv.mkDerivation rec {
   name = "microscheme-${version}";
@@ -10,15 +10,10 @@ stdenv.mkDerivation rec {
     sha256 = "1r3ng4pw1s9yy1h5rafra1rq19d3vmb5pzbpcz1913wz22qdd976";
   };
 
-  # Just a guess
-  propagatedBuildInputs = [ avrlibc ];
   buildInputs = [ makeWrapper vim ];
 
   installPhase = ''
     make install PREFIX=$out
-
-    wrapProgram $out/bin/microscheme \
-      --prefix PATH : "${stdenv.lib.makeBinPath [ avrdude avrgcc avrbinutils ]}"
   '';
 
   meta = with stdenv.lib; {