at91: fix at91_set_serial_console: use platform device id

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c
index c296045f..aacb19d 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -1168,7 +1168,7 @@
 {
 	if (portnr < ATMEL_MAX_UART) {
 		atmel_default_console_device = at91_uarts[portnr];
-		at91sam9rl_set_console_clock(portnr);
+		at91sam9rl_set_console_clock(at91_uarts[portnr]->id);
 	}
 }