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: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200601070444.16923-7-vigneshr@ti.com


Signed-off-by: Mark Brown <broonie@kernel.org>