arm: mvebu: turris_omnia: Enable NVMe support
PCIe-based NVMe SSD disks in M.2 2230/2242/2260 form-factor can be
connected to Turris Omnia mPCIe slot via passive M.2 <--> mPCIe adapter.
So enable PCIe NVMe drivers.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>