serial: add early_serial_setup() back to header file

early_serial_setup was removed from serial.h, but forgot to put in
serial_8250.h

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/frv/kernel/setup.c b/arch/frv/kernel/setup.c
index c1c32e4..a74c087 100644
--- a/arch/frv/kernel/setup.c
+++ b/arch/frv/kernel/setup.c
@@ -29,6 +29,7 @@
 #include <linux/serial.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
+#include <linux/serial_8250.h>
 
 #include <asm/setup.h>
 #include <asm/irq.h>