[PATCH] nvme: add back dependency on CONFIG_BLOCK

[Sagi Grimberg]

> A recent change removed the dependency on BLK_DEV_NVME, which implies
> the dependency on PCI and BLOCK. We don't need CONFIG_PCI, but without
> CONFIG_BLOCK we get tons of build errors, e.g.

Thanks Arnd, queued for the next round of rc fixes.

With a slight modification to the component in the subject line
(nvme-rdma).