scsi: pm8001: Provide function name 'pm8001_I_T_nexus_reset()' in header

Fixes the following W=1 kernel build warning(s):

 drivers/scsi/pm8001/pm8001_sas.c:989: warning: expecting prototype for and hard reset for(). Prototype was for pm8001_I_T_nexus_reset() instead

Link: https://lore.kernel.org/r/20210303144631.3175331-12-lee.jones@linaro.org
Cc: Jack Wang <jinpu.wang@cloud.ionos.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/pm8001/pm8001_sas.c

@@ -981,6 +981,7 @@ void pm8001_open_reject_retry(
 }
 
 /**
+ * pm8001_I_T_nexus_reset()
   * Standard mandates link reset for ATA  (type 0) and hard reset for
   * SSP (type 1) , only for RECOVERY
   * @dev: the device structure for the device to reset.