board: h2200: Delete an unnecessary make rule

We have a generic rule to generate .o file from *.S
in $(TOPDIR)/config.mk.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

board/h2200/Makefile

@@ -10,8 +10,5 @@ obj-y	:= h2200.o
 
 extra-y := h2200-header.bin
 
-$(obj)h2200-header.o: h2200-header.S
-	$(CC) $(CFLAGS) -c -o $@ $<
-
 $(obj)h2200-header.bin: $(obj)h2200-header.o
 	$(OBJCOPY) -O binary $< $@