m28evk: Remove 'all' target from Makefile

Remove 'all' target from Makefile, as this is unused code.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NMarek Vasut <marek.vasut@gmail.com>

board/denx/m28evk/Makefile

@@ -37,8 +37,6 @@ OBJS	:= $(addprefix $(obj),$(COBJS))
 $(LIB):	$(obj).depend $(OBJS)
 	$(call cmd_link_o_target, $(OBJS))
 
-all:	$(ALL)
-
 #########################################################################
 
 # defines $(obj).depend target