Add support for dumping the kernel address space layout to the console. User can enable CONFIG_DEBUG_VM to dump the virtual memory region into dmesg buffer during boot-up. Signed-off-by: Yash Shah <yash.shah@sifive.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Anup Patel <anup@brainfault.org> [paul.walmsley@sifive.com: dropped .init/.text/.data/.bss prints; added PCI legacy I/O region display] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>