Modify ufshcd_clear_cmd() such that it supports clearing multiple commands
at once instead of one command at a time. This change will be used in a
later patch to reduce the time spent in the reset handler.

Link: https://lore.kernel.org/r/20220613214442.212466-3-bvanassche@acm.orgReviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>