nvme: enable char device per namespace

[Javier González]

On 12.01.2021 19:33, Christoph Hellwig wrote:
>On Tue, Jan 12, 2021 at 07:30:55PM +0100, Javier González wrote:
>> I have not implemented multipath support, but it should definitely not
>> crash like this. I'll rebase to 5.11 and test.
>>
>> Christoph: Is it OK to send this without multipath or should I just send
>> all together?
>
>We're not in a rush at the moment, so I'd prefer working multipath
>support if you can spare a few cycles.

Sure. I'll work on that and submit all under the same patchset.