move help target to Makefile; it doesn't need config_host.mk

Change-Id: Ib627bb0a12b5b055f8d6077c00cc8099473fa176

Makefile

@@ -18,7 +18,7 @@ SRCDIR:=$(patsubst %/,%,$(dir $(realpath $(firstword $(MAKEFILE_LIST)))))
 .PHONY : $(filter-out $(SRCDIR)/config_host.mk,$(MAKECMDGOALS))
 
 # recursively invoke Makefile.top, which includes config_host.mk
-$(firstword $(MAKECMDGOALS)) : $(SRCDIR)/config_host.mk
+$(filter-out help,$(firstword $(MAKECMDGOALS))) : $(SRCDIR)/config_host.mk
 	$(MAKE) -r -f $(SRCDIR)/Makefile.top $(MAKECMDGOALS)
 
 # run configure in an environment not polluted by config_host.mk
@@ -34,4 +34,8 @@ $(SRCDIR)/config_host.mk : \
 $(SRCDIR)/autogen.lastrun:
 	@true
 
+help:
+	@cat $(SRCDIR)/solenv/gbuild/gbuild.help.txt
+	@true
+
 # vim: set noet sw=4 ts=4:

Makefile.top

@@ -527,14 +527,4 @@ debugrun:
 
 endif # not clean or distclean
 
-
-#########################
-# help
-#
-.PHONY: help
-help:
-	@cat $(SRCDIR)/solenv/gbuild/gbuild.help.txt
-	@true
-
-
 # vim: set noet sw=4 ts=4: