mtd: core: provide unique name for nvmem device, take two

mtd: core: provide unique name for nvmem device, take two

Commit c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
tries to give the nvmem device a unique name, but fails badly if the mtd
device doesn't have a "struct device" associated with it, i.e. if
CONFIG_MTD_PARTITIONED_MASTER is not set. This will result in the name
"(null)-user-otp", which is not unique. It seems the best we can do is
to use the compatible name together with a unique identifier added by
the nvmem subsystem by using NVMEM_DEVID_AUTO.

Fixes: c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-1-michael@walle.cc