mainboard/emulation: Use C89 comments style & remove commented code

Change-Id: I627338505fe1273366bc8f6f528d829b3162b371
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/16916
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/emulation/qemu-power8/mainboard.c

@@ -24,7 +24,7 @@ static void mainboard_enable(device_t dev)
 		die("No dev0; die\n");
 	}
 
-	// Where does RAM live?
+	/* Where does RAM live? */
 	ram_resource(dev, 0, 2048, 32768);
 	cbmem_recovery(0);
 }