Currently the nvmem core expect the config to provide a name and ID
that are then used to create the device name. When no device name is
given 'nvmem' is used. However if there is several such anonymous
devices they all get named 'nvmem0', which doesn't work.

To fix this problem use the ID from the config only when the config
also provides a name. When no name is provided take the uinque ID of
the nvmem device instead.
Signed-off-by: NAban Bedel <albeu@free.fr>
Reviewed-by: NMoritz Fischer <mdf@kernel.org>
Signed-off-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>