u-boot-initial-env: Add missing dependencies

When performing a build consisting of only a defconfig target and then
this tool, we were missing two dependencies. Add them.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/Makefile b/Makefile
index d4fedd8..41adac7 100644
--- a/Makefile
+++ b/Makefile
@@ -2512,7 +2512,7 @@
 	sed -e '/^\s*$$/d' | \
 	sort -t '=' -k 1,1 -s -o $@
 
-u-boot-initial-env: scripts_basic $(env_h) FORCE
+u-boot-initial-env: scripts_basic $(version_h) $(env_h) include/config.h FORCE
 	$(Q)$(MAKE) $(build)=tools $(objtree)/tools/printinitialenv
 	$(call if_changed,genenv)