Panic when boot_flow_init() failed

Small oversight from CL Ieae7fe4ef5b3047174ec0ad057e487660ccd5a03.
Hafnium would continue to execute even if it could not parse the FDT.
Add a panic() in the caller to correct it.

Also fix a dlog message missing a newline.

Bug: 117551352
Change-Id: I9024800232013f92431db173315dfd379081d7f9
diff --git a/src/cpu.c b/src/cpu.c
index 43efa26..ea66af2 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -105,7 +105,7 @@
 
 	if (!found_boot_cpu) {
 		/* Boot CPU was initialized but with wrong ID. */
-		dlog("Boot CPU's ID not found in config.");
+		dlog("Boot CPU's ID not found in config.\n");
 		cpus[0].id = boot_cpu_id;
 	}
 }