scsi: ufs: core: Introduce ufshcd_has_pending_tasks()

Prepare to remove hba->clk_gating.active_reqs check from
ufshcd_is_ufs_dev_busy().

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20241124070808.194860-2-avri.altman@wdc.com


Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>