hwmon: Include <linux/io.h> instead of <asm/io.h>

Drivers should be including <linux/io.h> instead of <asm/io.h>.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Cc: Nicolas Boichat <nicolas@boichat.ch>
Cc: Juerg Haefliger <juergh@gmail.com>
Cc: Frank Seidel <frank@f-seidel.de>
Acked-by: Jim Cromie <jim.cromie@gmail.com>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Cc: Roger Lucas <vt8231@hiddenengine.co.uk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>