scsi: ufs: Use the resource-managed function to add devfreq device

This patch uses the resource-managed to add the devfreq device.  This
function will make it easy to handle the devfreq device.

- struct devfreq *devm_devfreq_add_device(struct device *dev,
				  struct devfreq_dev_profile *profile,
				  const char *governor_name,
				  void *data);
Cc: Vinayak Holikatti <vinholikatti@gmail.com>
Cc: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -6250,8 +6250,6 @@ void ufshcd_remove(struct ufs_hba *hba)
 	ufshcd_hba_stop(hba, true);
 
 	ufshcd_exit_clk_gating(hba);
-	if (ufshcd_is_clkscaling_enabled(hba))
-		devfreq_remove_device(hba->devfreq);
 	ufshcd_hba_exit(hba);
 }
 EXPORT_SYMBOL_GPL(ufshcd_remove);
@@ -6579,7 +6577,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	}
 
 	if (ufshcd_is_clkscaling_enabled(hba)) {
-		hba->devfreq = devfreq_add_device(dev, &ufs_devfreq_profile,
+		hba->devfreq = devm_devfreq_add_device(dev, &ufs_devfreq_profile,
 						   "simple_ondemand", NULL);
 		if (IS_ERR(hba->devfreq)) {
 			dev_err(hba->dev, "Unable to register with devfreq %ld\n",