[$] Removing support for old hardware from the kernel

The kernel supports a wide range of hardware. Or, at least, the kernelcontains drivers for a lot of hardware, but the hardware for which many ofthose drivers was written is old and, perhaps, no longer in actual use.Some of those drivers would certainly no longer work even if the hardwarecould be found. These drivers provide no value, but they are still an ongoingmaintenance burden; it would be better to simply remove them from thekernel. But identifying which drivers can go is not as easy as one mightthink. Arnd Bergmann led an inconclusive session on this topic at the 2018Kernel Maintainers Summit.