Remove remaining bits of io_remap_page_range()

Commit 33bf5610

 ("feature removal of io_remap_page_range()") removed
io_remap_page_range(), but it is still included in some arch header
files.  It has no in-tree users.

Signed-off-by: Javi Merino <javi.merino@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>