nvme-pci: set min_align_mask before calculating max_hw_sectors

If swiotlb is force enabled dma_max_mapping_size ends up calling
swiotlb_max_mapping_size which takes into account the min align mask for
the device.  Set the min align mask for nvme driver before calling
dma_max_mapping_size while calculating max hw sectors.

Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>