Get the cpu IDs from the FDT.

These are the IDs used to identify cores in PSCI.

Change-Id: I9e88a6c69f963864591e39f0191cdd5ce824ce6d
diff --git a/src/plat.c b/src/plat.c
index d7d0566..2172d6b 100644
--- a/src/plat.c
+++ b/src/plat.c
@@ -83,6 +83,8 @@
 		goto out_unmap_fdt;
 	}
 
+	fdt_find_cpus(&n, p->cpu_ids, &p->cpu_count);
+
 	p->mem_ranges_count = 0;
 	fdt_find_memory_ranges(&n, p);