mtd: spi-nor: Add support for IS25LP032/064

The datasheet is publically available at
http://www.issi.com/WW/pdf/IS25LP032-064-128.pdf

. The parameters fit to
what is already available for IS25LP128/256.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>