[SCSI] aic7xxx: Take the LED out of diagnostic mode on PM resume

Take the Diag/Activity-LED of the HBA out of diagnostic mode on PM
resume after successful PM resume from standby and HBA restart, it
remained always on before. If something fails before complete
recovery, it should remain on, since it is a diagnostics LED, reason
for the used higher layer for the clear.

Signed-off-by:  <thomas.schorpp@gmail.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>