Makefile: Add target for combined spl/u-boot.bin & u-boot.img

This new make target "u-boot-img.bin" consists of the U-Boot
SPL image with the real, full-blown U-Boot image directly
attached to it. The full-blown U-Boot image has the mkimage
header included, with its load-address and entry-point.

This will be used by the upcoming a3m071 MPC5200 board port.

Signed-off-by: Stefan Roese <sr@denx.de>

Makefile

@@ -544,6 +544,9 @@ $(obj)u-boot-$(nodtb)-tegra.bin: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin $(dtb
 		rm $(obj)spl/u-boot-spl-pad.bin
 endif
 
+$(obj)u-boot-img.bin: $(obj)spl/u-boot-spl.bin $(obj)u-boot.img
+		cat $(obj)spl/u-boot-spl.bin $(obj)u-boot.img > $@
+
 ifeq ($(CONFIG_SANDBOX),y)
 GEN_UBOOT = \
 		cd $(LNDIR) && $(CC) $(SYMS) -T $(obj)u-boot.lds \