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

Change-Id: I0014fc030888d71f7951c97bccc7cef0e1c45186
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/16922
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/mainboard/aopen/dxplplusu/romstage.c b/src/mainboard/aopen/dxplplusu/romstage.c
index 5e7a159..3fba1ad 100644
--- a/src/mainboard/aopen/dxplplusu/romstage.c
+++ b/src/mainboard/aopen/dxplplusu/romstage.c
@@ -46,14 +46,14 @@
 		},
 	};
 
-	// Get the serial port running and print a welcome banner
+	/* Get the serial port running and print a welcome banner */
 	lpc47m10x_enable_serial(SERIAL_DEV, CONFIG_TTYS0_BASE);
 	console_init();
 
-	// Halt if there was a built in self test failure
+	/* Halt if there was a built in self test failure */
 	report_bist_failure(bist);
 
-	// If this is a warm boot, some initialization can be skipped
+	/* If this is a warm boot, some initialization can be skipped */
 	if (!e7505_mch_is_ready()) {
 		enable_smbus();