mtd: spi-nor: winbond: Add W25H02NWxxAM CMP locking support

mtd: spi-nor: winbond: Add W25H02NWxxAM CMP locking support

This chip has support for the locking complement (CMP) feature. Add
the relevant bit to enable it.

Unfortunately, this chip also comes with an incorrect BFPT table,
indicating the Control Register cannot be read back. This is wrong,
reading back the register works and has no (observed) side effect. The
datasheet clearly indicates supporting the 35h command and all bits from
the CR are marked readable. QE and CMP bits are inside, and can be
properly read back.

Add a fixup for this, otherwise it would defeat the use of the CMP
feature.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>