npu: Fix broken fast reset

0679f61 "fast-reset: by default (if possible)" broke NPU - now
the NV links does not get enabled after reboot.

This disables fast reboot for NPU machines till a better solution is found.

Suggested-by: Andrew Donnellan <andonnel@au1.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

hw/npu.c

@@ -1153,6 +1153,9 @@ static void npu_probe_phb(struct dt_node *dn)
 	dt_add_property_cells(np, "ibm,links", links);
 	dt_add_property(np, "ibm,mmio-window", mm_win, sizeof(mm_win));
 	dt_add_property_cells(np, "ibm,phb-diag-data-size", 0);
+
+	/* Disable fast reboot - not currently supported */
+	disable_fast_reboot("NVLink device enabled");
 }
 
 static void npu_dev_populate_vendor_cap(struct npu_dev_cap *cap)