sh: Update sh timer function

Change to write/readX function and fix timer problem.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/cpu/sh4/Makefile b/cpu/sh4/Makefile
index d3c5eef..3c96a49 100644
--- a/cpu/sh4/Makefile
+++ b/cpu/sh4/Makefile
@@ -29,7 +29,7 @@
 LIB	= $(obj)lib$(CPU).a
 
 SOBJS	= start.o
-COBJS	= cpu.o interrupts.o watchdog.o time.o cache.o
+COBJS	= cpu.o interrupts.o watchdog.o cache.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))