[PATCH] nvme: don't always build constants.o

[Keith Busch]

On Mon, Jul 18, 2022 at 07:12:52AM +0200, Christoph Hellwig wrote:
> The entire content of constants.c if guarded by an ifdef, so switch to
> just building the file conditionally instead.

Looks good.

Reviewed-by: Keith Busch <kbusch at kernel.org>