scsi: myrs: Don't use GFP_DMA

The myrs devices supports 64-bit addressing, so remove the spurious GFP_DMA
allocations.

Link: https://lore.kernel.org/r/20211222091935.925624-1-hch@lst.de


Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>