Building ufshcd-pltfrm.c on arch/s390/ has a linker error since S390 does
not support IOMEM, so add a dependency on HAS_IOMEM.

s390-linux-ld: drivers/scsi/ufs/ufshcd-pltfrm.o: in function `ufshcd_pltfrm_init':
ufshcd-pltfrm.c:(.text+0x38e): undefined reference to `devm_platform_ioremap_resource'

where that devm_ function is inside an #ifdef CONFIG_HAS_IOMEM/#endif
block.

Link: lore.kernel.org/r/202101031125.ZEFCUiKi-lkp@intel.com
Link: https://lore.kernel.org/r/20210106040822.933-1-rdunlap@infradead.org
Fixes: 03b1781a ("[SCSI] ufs: Add Platform glue driver for ufshcd")
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Avri Altman <avri.altman@wdc.com>
Cc: linux-scsi@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>