scsi: ufs: core: Remove irrelevant reference to non-existing doc

Remove all references to the description of __ufshcd_wl_{suspend,resume} as
no such description exist.

Fixes: b294ff3e (scsi: ufs: core: Enable power management for wlun)
Link: https://lore.kernel.org/r/20210603122209.635799-1-avri.altman@wdc.com


Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>