What this person paid $40,000 for is access to development kits for certain hardware, which with chip vendors like that usually also comes with support. The vendor cannot prevent you from exercising your GPLv2 rights after they hand you the code. In fact, if you manufacture and distribute a device that uses these kernel patches it becomes your obligation to enable your customers to exercise their GPLv2 rights. Chip manufacturers know this and (if they are somewhat reputable) usually license their code appropriately.