mtd: spi-nor: cadence-quadspi: Drop redundant WREN in erase path

Drop redundant WREN command in cqspi_erase() as SPI NOR core takes care
of sending WREN command before sending erase command.
Signed-off-by: NVignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200601070444.16923-7-vigneshr@ti.comSigned-off-by: NMark Brown <broonie@kernel.org>

drivers/mtd/spi-nor/controllers/cadence-quadspi.c

@@ -1016,11 +1016,6 @@ static int cqspi_erase(struct spi_nor *nor, loff_t offs)
 	if (ret)
 		return ret;
 
-	/* Send write enable, then erase commands. */
-	ret = nor->controller_ops->write_reg(nor, SPINOR_OP_WREN, NULL, 0);
-	if (ret)
-		return ret;
-
 	/* Set up command buffer. */
 	ret = cqspi_command_write_addr(nor, nor->erase_opcode, offs);
 	if (ret)