scsi: hisi_sas: fix SATA breakpoint memory size

scsi: hisi_sas: fix SATA breakpoint memory size

Currently the size of memory we allocate for SATA breakpoint buffer is
incorrect.

The breakpoint memory size should be as follows: 32 (NCQ tags) * 128 *
2048 (max #devs) = 8MB

Currently we only allocate 0.5MB, but get away with it as we never
have SATA device index > 128 typically.

To conserve precious DMA memory (8MB may not be even available), limit
the number of devices per HBA to 1024, which means 4MB of memory
required for SATA breakpoint.

The 1024 device limit applied to all HW versions. For v3 hw, we need
to configure this value.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>