mtd: nand: allow NAND_NO_SUBPAGE_WRITE to be set from driver

mtd: nand: allow NAND_NO_SUBPAGE_WRITE to be set from driver

commit bf7a01bf7987b63b121d572b240c132ec44129c4 upstream.

The NAND_CHIPOPTIONS_MSK has limited utility and is causing real bugs. It
silently masks off at least one flag that might be set by the driver
(NAND_NO_SUBPAGE_WRITE). This breaks the GPMI NAND driver and possibly
others.

Really, as long as driver writers exercise a small amount of care with
NAND_* options, this mask is not necessary at all; it was only here to
prevent certain options from accidentally being set by the driver. But the
original thought turns out to be a bad idea occasionally. Thus, kill it.

Note, this patch fixes some major gpmi-nand breakage.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Huang Shijie <shijie8@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
[Brian Norris: This is a backport for v3.2 stable.]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>