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/mips/mipssim/sim_setup.c b/arch/mips/mipssim/sim_setup.c
index 60e6690..17819b5 100644
--- a/arch/mips/mipssim/sim_setup.c
+++ b/arch/mips/mipssim/sim_setup.c
@@ -26,6 +26,7 @@
 #include <linux/tty.h>
 #include <linux/serial.h>
 #include <linux/serial_core.h>
+#include <linux/serial_8250.h>
 
 #include <asm/cpu.h>
 #include <asm/bootinfo.h>