[PATCH] Use linux/io.h instead of asm/io.h

In preparation for moving check_signature, change these users from asm/io.h
to linux/io.h

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>