M28: Add MMC SPL

This patch adds SPL code for the M28 board.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
diff --git a/board/denx/m28evk/Makefile b/board/denx/m28evk/Makefile
index e6aba9a..47229e6 100644
--- a/board/denx/m28evk/Makefile
+++ b/board/denx/m28evk/Makefile
@@ -25,7 +25,13 @@
 
 LIB	= $(obj)lib$(BOARD).o
 
+ifndef	CONFIG_SPL_BUILD
 COBJS	:= m28evk.o
+endif
+
+ifdef	CONFIG_SPL_BUILD
+COBJS	:= mem_init.o mmc_boot.o power_init.o
+endif
 
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))
@@ -33,6 +39,8 @@
 $(LIB):	$(obj).depend $(OBJS)
 	$(call cmd_link_o_target, $(OBJS))
 
+all:	$(ALL)
+
 #########################################################################
 
 # defines $(obj).depend target