pch_phub: Improve ADE(Address Decode Enable) control

pch_phub: Improve ADE(Address Decode Enable) control

commit 9914a0de7a27ef2cb5d9aacfe50ae97ebb532f28 upstream.

Currently, external ROM access is enabled/disabled in probe()/remove().
So, when a buggy software access unanticipated memory area,
in case of enabling this ADE bit,
external ROM memory area can be broken.

This patch enables the ADE bit only accessing external ROM area.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Cc: Masayuki Ohtak <masa-korg@dsn.okisemi.com>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Denis Turischev <denis@compulab.co.il>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>