libflash: Support Micron N25Q256Ax NOR flash
libflash: Support Micron N25Q256Ax NOR flash

This 32MB part is used for the Barreleye OpenBMC BMC.

Signed-off-by: Joel Stanley <4816dabf8db1bc6cac35b3a24cab2ff844b5b0c7@jms.id.au>
Reviewed-by: Cédric Le Goater <2d8cace2254d4e43578d21933db015d84bcc468a@fr.ibm.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

legoater/skiboot,open-power/skiboot,open-power/skiboot,open-power/skiboot,mikey/skiboot,mikey/skiboot,qemu/skiboot,qemu/skiboot,legoater/skiboot,legoater/skiboot,shenki/skiboot,legoater/skiboot,stewart-ibm/skiboot,shenki/skiboot,shenki/skiboot,shenki/skiboot,legoater/skiboot,open-power/skiboot,shenki/skiboot,open-power/skiboot,qemu/skiboot,qemu/skiboot,mikey/skiboot,qemu/skiboot,stewart-ibm/skiboot,stewart-ibm/skiboot