Add Orion5x support to 16550 device driver

This patch provides access to the 16550-compatible
serial device of the Orion5x SoC.

Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index 8eda95cd..1073ac0 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -30,6 +30,9 @@
 #ifdef CONFIG_KIRKWOOD
 #include <asm/arch/kirkwood.h>
 #endif
+#ifdef CONFIG_ORION5X
+#include <asm/arch/orion5x.h>
+#endif
 
 #if defined (CONFIG_SERIAL_MULTI)
 #include <serial.h>