Config.mk: replace dependency to genpath with actual target

genpath is a detail of buildmakevars2file. Replace the dependency to
genpath with the actual buildmakevars2file target. This change by
itself does not fix any bug. Upcoming changes will add dependencies to
$(target), but no rule exist to create $(target).

To force a rebuild of the $(1) rule the target now depends on the
existing .phony target. This dummy target is already used elsewhere in
the code.

No change in behaviour is expected by this patch.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

stubdom/Makefile

@@ -48,18 +48,18 @@ TARGET_LDFLAGS += -nostdlib -L$(CROSS_PREFIX)/$(GNU_TARGET_ARCH)-xen-elf/lib
 
 TARGETS=$(STUBDOM_TARGETS)
 
-.PHONY: all
-all: build
-ifeq ($(STUBDOM_SUPPORTED),1)
-build: genpath $(STUBDOM_BUILD)
-else
-build: genpath
-endif
-
 STUBDOMPATH="stubdompath.sh"
 genpath-target = $(call buildmakevars2file,$(STUBDOMPATH))
 $(eval $(genpath-target))
 
+.PHONY: all
+all: build
+ifeq ($(STUBDOM_SUPPORTED),1)
+build: $(STUBDOMPATH) $(STUBDOM_BUILD)
+else
+build: $(STUBDOMPATH)
+endif
+
 ##############
 # Cross-newlib
 ##############
@@ -450,9 +450,9 @@ xenstore-stubdom: mini-os-$(XEN_TARGET_ARCH)-xenstore libxc xenstore
 #########
 
 ifeq ($(STUBDOM_SUPPORTED),1)
-install: genpath install-readme $(STUBDOM_INSTALL)
+install: $(STUBDOMPATH) install-readme $(STUBDOM_INSTALL)
 else
-install: genpath
+install: $(STUBDOMPATH)
 endif
 
 install-readme: