mtd: spi-nor: Add the SPI_NOR_XSR_RDY flag

S3AN flashes use a specific opcode to read the status register.
We currently use the SPI_S3AN flag to decide whether this specific
SR read opcode should be used, but SPI_S3AN is about to disappear, so
let's add a new flag.

Note that we use the same bit as SPI_S3AN implies SPI_NOR_XSR_RDY and
vice versa.
Signed-off-by: NBoris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: NVignesh Raghavendra <vigneshr@ti.com>

drivers/mtd/spi-nor/spi-nor.c

@@ -211,6 +211,14 @@ struct flash_info {
 					 * bit. Must be used with
 					 * SPI_NOR_HAS_LOCK.
 					 */
+#define SPI_NOR_XSR_RDY		BIT(10)	/*
+					 * S3AN flashes have specific opcode to
+					 * read the status register.
+					 * Flags SPI_NOR_XSR_RDY and SPI_S3AN
+					 * use the same bit as one implies the
+					 * other, but we will get rid of
+					 * SPI_S3AN soon.
+					 */
 #define	SPI_S3AN		BIT(10)	/*
 					 * Xilinx Spartan 3AN In-System Flash
 					 * (MFR cannot be used for probing
@@ -4799,7 +4807,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	 * spi_nor_wait_till_ready(). Xilinx S3AN share MFR
 	 * with Atmel spi-nor
 	 */
-	if (info->flags & SPI_S3AN)
+	if (info->flags & SPI_NOR_XSR_RDY)
 		nor->flags |=  SNOR_F_READY_XSR_RDY;
 
 	if (info->flags & SPI_NOR_HAS_LOCK)