phb4: Quieten and improve "Timeout waiting for electrical link"

This happens normally if a slot doesn't have a working HW presence
detect and relies instead of inband presence detect.

The message we display is scary and not very useful unless ou
are debugging, so quiten it up and change it to something more
meaningful.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-By: Michael Neuling <mikey@neuling.org>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

hw/phb4.c

@@ -2641,9 +2641,8 @@ static int64_t phb4_poll_link(struct pci_slot *slot)
 		}
 
 		if (slot->retries-- == 0) {
-			PHBERR(p, "LINK: Timeout waiting for electrical link\n");
-			PHBDBG(p, "LINK: DLP train control: 0x%016llx\n", reg);
-			return OPAL_HARDWARE;
+			PHBDBG(p, "LINK: No in-band presence\n");
+			return OPAL_SUCCESS;
 		}
 		/* Retry */
 		return pci_slot_set_sm_timeout(slot, msecs_to_tb(10));