mtd: spi-nor: Fix address width on flash chips > 16MB

If a flash chip has more than 16MB capacity but its BFPT reports
BFPT_DWORD1_ADDRESS_BYTES_3_OR_4, the spi-nor framework defaults to 3.

The check in spi_nor_set_addr_width() doesn't catch it because addr_width
did get set. This fixes that check.

Fixes: f9acd7fa ("mtd: spi-nor: sfdp: default to addr_width of 3 for configurable widths")
Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Cédric Le Goater <clg@kaod.org>
Link: https://lore.kernel.org/r/20201006132346.12652-1-bert@biot.com

drivers/mtd/spi-nor/core.c

@@ -3008,13 +3008,15 @@ static int spi_nor_set_addr_width(struct spi_nor *nor)
 		/* already configured from SFDP */
 	} else if (nor->info->addr_width) {
 		nor->addr_width = nor->info->addr_width;
-	} else if (nor->mtd.size > 0x1000000) {
-		/* enable 4-byte addressing if the device exceeds 16MiB */
-		nor->addr_width = 4;
 	} else {
 		nor->addr_width = 3;
 	}
 
+	if (nor->addr_width == 3 && nor->mtd.size > 0x1000000) {
+		/* enable 4-byte addressing if the device exceeds 16MiB */
+		nor->addr_width = 4;
+	}
+
 	if (nor->addr_width > SPI_NOR_MAX_ADDR_WIDTH) {
 		dev_dbg(nor->dev, "address width is too large: %u\n",
 			nor->addr_width);