CHROMIUM: nm10_gpio: support up to 96 GPIOs

CHROMIUM: nm10_gpio: support up to 96 GPIOs

The Intel 6 Series chipset supports 96 GPIOs while NM10 supports 64.
Added support for 64 or 96 GPIOs based on device ID.

BUG=chrome-os-partner:5368
TEST=run crossystem and ensure that the current values of dev, recovery and
write protect switches are correctly reported.

Change-Id: I60f778117349766a82867db664765911e27bc9e2
Signed-off-by: Sameer Nanda <snanda@chromium.org>
Reviewed-on: http://gerrit.chromium.org/gerrit/7004
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>