nvme-pci: set min_align_mask

The PRP addressing scheme requires all PRP entries except for the
first one to have a zero offset into the NVMe controller pages (which
can be different from the Linux PAGE_SIZE).  Use the min_align_mask
device parameter to ensure that swiotlb does not change the address
of the buffer modulo the device page size to ensure that the PRPs
won't be malformed.

Signed-off-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>