scsi: ufs: Fix build warning without CONFIG_PM

drivers/scsi/ufs/ufshcd.c:9770:12: warning: ‘ufshcd_rpmb_resume’ defined but not used [-Wunused-function]
 static int ufshcd_rpmb_resume(struct device *dev)
            ^~~~~~~~~~~~~~~~~~
drivers/scsi/ufs/ufshcd.c:9037:12: warning: ‘ufshcd_wl_runtime_resume’ defined but not used [-Wunused-function]
 static int ufshcd_wl_runtime_resume(struct device *dev)
            ^~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/ufs/ufshcd.c:9017:12: warning: ‘ufshcd_wl_runtime_suspend’ defined but not used [-Wunused-function]
 static int ufshcd_wl_runtime_suspend(struct device *dev)
            ^~~~~~~~~~~~~~~~~~~~~~~~~

Move it into #ifdef block to fix this.

Link: https://lore.kernel.org/r/20210617031326.36908-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>