scsi: ufs: hisi: fix ufs_hba_variant_ops passing

Without CONFIG_OF, the of_match_node() helper does not evaluate its
argument, and the compiler warns about the unused variable:

drivers/scsi/ufs/ufs-hisi.c: In function 'ufs_hisi_probe':
drivers/scsi/ufs/ufs-hisi.c:673:17: error: unused variable 'dev' [-Werror=unused-variable]

Rework this code to pass the data directly, and while we're at it,
correctly handle the const pointers.

Fixes: 653fcb07

 ("scsi: ufs: Add HI3670 SoC UFS driver support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>