What platform is nds4droid on for the nintendo ds with a license of gpl v2?
CREATE TABLE "nintendo_ds" (
  "name" text,
  "current_version" text,
  "system" text,
  "platform" text,
  "license" text
);
SELECT "platform" FROM "nintendo_ds" WHERE "system"='nintendo ds' AND "license"='gpl v2' AND "name"='nds4droid';