ppc/pnv: Use QOM hierarchy to scan PEC PHB4 devices

When -nodefaults is supported for PHB4 devices, the pecs array under
the chip will be empty. This will break the 'info pic' HMP command.

Do a QOM loop on the chip children and look for PEC PHB4 devices
instead.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20211213132830.108372-15-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/ppc/pnv.c

@@ -659,20 +659,26 @@ static void pnv_chip_power8_pic_print_info(PnvChip *chip, Monitor *mon)
                          pnv_chip_power8_pic_print_info_child, mon);
 }
 
+static int pnv_chip_power9_pic_print_info_child(Object *child, void *opaque)
+{
+    Monitor *mon = opaque;
+    PnvPHB4 *phb4 = (PnvPHB4 *) object_dynamic_cast(child, TYPE_PNV_PHB4);
+
+    if (phb4) {
+        pnv_phb4_pic_print_info(phb4, mon);
+    }
+    return 0;
+}
+
 static void pnv_chip_power9_pic_print_info(PnvChip *chip, Monitor *mon)
 {
     Pnv9Chip *chip9 = PNV9_CHIP(chip);
-    int i, j;
 
     pnv_xive_pic_print_info(&chip9->xive, mon);
     pnv_psi_pic_print_info(&chip9->psi, mon);
 
-    for (i = 0; i < chip->num_pecs; i++) {
-        PnvPhb4PecState *pec = &chip9->pecs[i];
-        for (j = 0; j < pec->num_stacks; j++) {
-            pnv_phb4_pic_print_info(&pec->stacks[j].phb, mon);
-        }
-    }
+    object_child_foreach_recursive(OBJECT(chip),
+                         pnv_chip_power9_pic_print_info_child, mon);
 }
 
 static uint64_t pnv_chip_power8_xscom_core_base(PnvChip *chip,