mtd: st_spi_fsm: remove unused field from struct stfsm

The 'region' field in struct stfsm is unused and can be removed.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/devices/st_spi_fsm.c

@@ -255,7 +255,6 @@ struct stfsm_seq {
 struct stfsm {
 	struct device		*dev;
 	void __iomem		*base;
-	struct resource		*region;
 	struct mtd_info		mtd;
 	struct mutex		lock;
 	struct flash_info       *info;