Makefile: add support to generate LZMA compressed u-boot image

This patch adds support for generating LZMA compressed u-boot image.
The compressed image can be used for SPL to reduce the size of the u-boot
binary.

Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>

Makefile

@@ -1002,6 +1002,9 @@ append = cat $(filter-out $< $(PHONY), $^) >> $@
 quiet_cmd_pad_cat = CAT     $@
 cmd_pad_cat = $(cmd_objcopy) && $(append) || rm -f $@
 
+quiet_cmd_lzma = LZMA    $@
+cmd_lzma = lzma -c -z -k -9 $< > $@
+
 cfg: u-boot.cfg
 
 quiet_cmd_cfgcheck = CFGCHK  $2
@@ -1384,6 +1387,16 @@ else
 UBOOT_BIN := u-boot.bin
 endif
 
+MKIMAGEFLAGS_u-boot-lzma.img = -A $(ARCH) -T standalone -C lzma -O u-boot \
+	-a $(CONFIG_SYS_TEXT_BASE) -e $(CONFIG_SYS_UBOOT_START) \
+	-n "U-Boot $(UBOOTRELEASE) for $(BOARD) board"
+
+u-boot.bin.lzma: u-boot.bin FORCE
+	$(call if_changed,lzma)
+
+u-boot-lzma.img: u-boot.bin.lzma FORCE
+	$(call if_changed,mkimage)
+
 u-boot-dtb.img u-boot.img u-boot.kwb u-boot.pbl u-boot-ivt.img: \
 		$(if $(CONFIG_SPL_LOAD_FIT),u-boot-nodtb.bin \
 			$(if $(CONFIG_OF_SEPARATE)$(CONFIG_OF_EMBED)$(CONFIG_OF_HOSTFILE),dts/dt.dtb) \