kcore: use registerd physmem information

For /proc/kcore, each arch registers its memory range by kclist_add().
In usual,

	- range of physical memory
	- range of vmalloc area
	- text, etc...

are registered but "range of physical memory" has some troubles.  It
doesn't updated at memory hotplug and it tend to include unnecessary
memory holes.  Now, /proc/iomem (kernel/resource.c) includes required
physical memory range information and it's properly updated at memory
hotplug.  Then, it's good to avoid using its own code(duplicating
information) and to rebuild kclist for physical memory based on
/proc/iomem.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/mips/mm/init.c

@@ -352,7 +352,6 @@ void __init paging_init(void)
 	free_area_init_nodes(max_zone_pfns);
 }
 
-static struct kcore_list kcore_mem;
 #ifdef CONFIG_64BIT
 static struct kcore_list kcore_kseg0;
 #endif
@@ -412,7 +411,6 @@ void __init mem_init(void)
 		kclist_add(&kcore_kseg0, (void *) CKSEG0,
 				0x80000000 - 4, KCORE_TEXT);
 #endif
-	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT, KCORE_RAM);
 
 	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 	       "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",