kbuild: make dependencies in scripts/Makefile.autoconf more readable

I do not remember why I wrote the code like this, but let's make it
a bit more readable.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

scripts/Makefile.autoconf

@@ -46,7 +46,7 @@ quiet_cmd_autoconf_dep = GEN     $@
 	-MQ include/config/auto.conf $(srctree)/include/common.h > $@ || {	\
 		rm $@; false;							\
 	}
-include/autoconf.mk.dep: FORCE
+include/autoconf.mk.dep: include/config.h FORCE
 	$(call cmd,autoconf_dep)
 
 # We are migrating from board headers to Kconfig little by little.
@@ -71,20 +71,17 @@ quiet_cmd_autoconf = GEN     $@
 		rm $@.tmp; false;							\
 	}
 
-include/autoconf.mk: FORCE
+include/autoconf.mk: include/config.h FORCE
 	$(call cmd,autoconf)
 
-spl/include/autoconf.mk: FORCE
+spl/include/autoconf.mk: include/config.h FORCE
 	$(Q)mkdir -p $(dir $@)
 	$(call cmd,autoconf,-DCONFIG_SPL_BUILD)
 
-tpl/include/autoconf.mk: FORCE
+tpl/include/autoconf.mk: include/config.h FORCE
 	$(Q)mkdir -p $(dir $@)
 	$(call cmd,autoconf,-DCONFIG_SPL_BUILD -DCONFIG_TPL_BUILD)
 
-include/autoconf.mk include/autoconf.mk.dep \
-	spl/include/autoconf.mk tpl/include/autoconf.mk: include/config.h
-
 # include/config.h
 # Prior to Kconfig, it was generated by mkconfig. Now it is created here.
 define filechk_config_h