treewide: Add lots of platforms to packages with no meta

Build-tested on x86_64 Linux and on Darwin.

pkgs/data/fonts/dejavu-fonts/default.nix

@@ -39,4 +39,8 @@ stdenv.mkDerivation rec {
         cp $i $out/share/fonts/truetype;
     done;
   '';
+
+  meta = {
+    platforms = stdenv.lib.platforms.linux;
+  };
 }

pkgs/data/fonts/mph-2b-damase/default.nix

@@ -18,4 +18,8 @@ stdenv.mkDerivation {
     mkdir -p $out/share/fonts/truetype
     cp *.ttf $out/share/fonts/truetype
   '';
+
+  meta = {
+    platforms = stdenv.lib.platforms.unix;
+  };
 }

pkgs/data/fonts/ttf-bitstream-vera/default.nix

@@ -15,4 +15,8 @@ stdenv.mkDerivation {
     mkdir -p $fontDir
     cp *.ttf $fontDir
   '';
+
+  meta = {
+    platforms = stdenv.lib.platforms.unix;
+  };
 }