phb4: Fix PCIe GEN4 on DD2.1 and above

In this change:
  eef0e19 PHB4: Default to PCIe GEN3 on POWER9 DD2.00

We clamped DD2.00 parts to GEN3 but unfortunately this change also
applies to DD2.1 and above.

This fixes this to only apply to DD2.00.

This also cleans up the documentation and printing.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

hw/phb4.c

@@ -4895,14 +4895,13 @@ static void phb4_create(struct dt_node *np)
 	if (!phb4_read_capabilities(p))
 		goto failed;
 
-	/* Priority order: NVRAM -> dt -> GEN2 dd1 -> GEN4 */
+	/* Priority order: NVRAM -> dt -> GEN2 dd1 -> GEN3 dd2.00 -> GEN4 */
 	p->max_link_speed = 4;
 	if (p->rev == PHB4_REV_NIMBUS_DD10)
 		p->max_link_speed = 2;
-	if (p->rev == PHB4_REV_NIMBUS_DD20 && chip->ec_rev == 0) {
+	if (p->rev == PHB4_REV_NIMBUS_DD20 &&
+	    chip->ec_level == 0 && chip->ec_rev == 0)
 		p->max_link_speed = 3;
-		PHBINF(p, "Default max link speed for P9 DD2.00 is GEN3\n");
-	}
 	if (dt_has_node_property(np, "ibm,max-link-speed", NULL))
 		p->max_link_speed = dt_prop_get_u32(np, "ibm,max-link-speed");
 	if (pcie_max_link_speed)