s3c24x0: move serial driver to drivers/serial

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/cpu/arm920t/s3c24x0/Makefile b/cpu/arm920t/s3c24x0/Makefile
index 6764920..8fd525e 100644
--- a/cpu/arm920t/s3c24x0/Makefile
+++ b/cpu/arm920t/s3c24x0/Makefile
@@ -25,8 +25,7 @@
 
 LIB	= $(obj)lib$(SOC).a
 
-COBJS	= i2c.o interrupts.o serial.o speed.o \
-	  usb.o usb_ohci.o nand.o
+COBJS	= i2c.o interrupts.o speed.o usb.o usb_ohci.o nand.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))