mtd: spi-nor: macronix: Fix name for mx66l51235f

According to macronix website, there is no mx66l51235l part number.
The chip detected as such is actually mx66l51235f. Rename the flash.
Do not update the mx66l51235l name from the spi_nor_dev_ids[], since
there are dt that are using this compatible.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>