linux-imx

NVMe: Add a pci_driver shutdown method

We need to shut down the device cleanly when the system is being shut down.
This was in an earlier patch but was inadvertently lost during a rewrite.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>