mtd: spi-nor: support lock/unlock/is_locked for Winbond

Many other flash share the same features as ST Micro. I've tested some
Winbond flash, so add them.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 192aa8c..5309920 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1215,8 +1215,9 @@
 	mtd->_erase = spi_nor_erase;
 	mtd->_read = spi_nor_read;
 
-	/* NOR protection support for STmicro/Micron chips */
-	if (JEDEC_MFR(info) == SNOR_MFR_MICRON) {
+	/* NOR protection support for STmicro/Micron chips and similar */
+	if (JEDEC_MFR(info) == SNOR_MFR_MICRON ||
+	    JEDEC_MFR(info) == SNOR_MFR_WINBOND) {
 		nor->flash_lock = stm_lock;
 		nor->flash_unlock = stm_unlock;
 		nor->flash_is_locked = stm_is_locked;