image: Split FIT code into new image-fit.c

The FIT code is about half the size of the >3000-line image.c. Split this
code into its own file.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>

common/Makefile

@@ -231,6 +231,7 @@ COBJS-$(CONFIG_BOUNCE_BUFFER) += bouncebuf.o
 COBJS-y += console.o
 COBJS-y += dlmalloc.o
 COBJS-y += image.o
+COBJS-$(CONFIG_FIT) += image-fit.o
 COBJS-y += memsize.o
 COBJS-y += stdio.o
 

tools/Makefile

@@ -78,6 +78,7 @@ BIN_FILES-$(CONFIG_KIRKWOOD) += kwboot$(SFX)
 # Source files which exist outside the tools directory
 EXT_OBJ_FILES-$(CONFIG_BUILD_ENVCRC) += common/env_embedded.o
 EXT_OBJ_FILES-y += common/image.o
+EXT_OBJ_FILES-$(CONFIG_FIT) += common/image-fit.o
 EXT_OBJ_FILES-y += lib/crc32.o
 EXT_OBJ_FILES-y += lib/md5.o
 EXT_OBJ_FILES-y += lib/sha1.o
@@ -209,6 +210,7 @@ $(obj)mkimage$(SFX):	$(obj)aisimage.o \
 			$(obj)crc32.o \
 			$(obj)default_image.o \
 			$(obj)fit_image.o \
+			$(obj)image-fit.o \
 			$(obj)image.o \
 			$(obj)imximage.o \
 			$(obj)kwbimage.o \