scsi: mpi3mr: Select CONFIG_SCSI_SAS_ATTRS

Starting with commit 42fc9fee ("scsi: mpi3mr: Add helper functions to
manage device's port"), kernel configured with CONFIG_SCSI_MPI3MR=m and
CONFIG_SCSI_SAS_ATTRS=n fails to build because modpost cannot find symbols
used in mpi3mr_transport.c:

  ERROR: modpost: "sas_port_alloc_num" [drivers/scsi/mpi3mr/mpi3mr.ko] undefined!
  ERROR: modpost: "sas_remove_host" [drivers/scsi/mpi3mr/mpi3mr.ko] undefined!
  ERROR: modpost: "sas_phy_alloc" [drivers/scsi/mpi3mr/mpi3mr.ko] undefined!
  ERROR: modpost: "sas_phy_free" [drivers/scsi/mpi3mr/mpi3mr.ko] undefined!
  ...

Select CONFIG_SCSI_SAS_ATTRS when CONFIG_SCSI_MPI3MR is enabled to prevent
inconsistent configs.

Link: https://lore.kernel.org/r/20221017145517.93BCB6043B@lion.mk-sys.cz
Fixes: 42fc9fee ("scsi: mpi3mr: Add helper functions to manage device's port")
Acked-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpi3mr/Kconfig

@@ -4,5 +4,6 @@ config SCSI_MPI3MR
 	tristate "Broadcom MPI3 Storage Controller Device Driver"
 	depends on PCI && SCSI
 	select BLK_DEV_BSGLIB
+	select SCSI_SAS_ATTRS
 	help
 	MPI3 based Storage & RAID Controllers Driver.