scsi: libsas: Add LIBSAS_SHT_BASE

scsi: libsas: Add LIBSAS_SHT_BASE

There is much duplication in the scsi_host_template structure for the
drivers which use libsas.

Similar to how a standard template is used in libata with __ATA_BASE_SHT,
create a standard template in LIBSAS_SHT_BASE.

Don't set a default for max_sectors at SCSI_DEFAULT_MAX_SECTORS, as
scsi_host_alloc() will default to this value automatically.

Even though some drivers don't set proc_name, it won't make much difference
to set as DRV_NAME.

Also add LIBSAS_SHT_BASE_NO_SLAVE_INIT for the hisi_sas drivers which have
custom .slave_alloc and .slave_configure methods.

Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240308114339.1340549-2-john.g.garry@oracle.com
Reviewed-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>