[PATCH] w1: remove drivers/w1/w1.h

drivers/w1/w1_io.h is both a subset of drivers/w1/w1.h and no longer
#include'd by any file.

This patch therefore removes w1_io.h.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>