Fix specific targets for UIConfig submodules

For instance,

make UIConfig_uui

allows to run the UIConfig target for the uui module. Submodules are called
for instance modules/swriter, but

make UIConfig_modules/swriter

was not working only because the main Makefile didn't include the generic
target.  This adds the generic target, thus fixing the issue.

Change-Id: I6825fa5bf0daa4d964bea651841e8fac318fe068
Reviewed-on: https://gerrit.libreoffice.org/49825Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Jenkins <ci@libreoffice.org>

Makefile.in

@@ -162,7 +162,7 @@ gbuild_TARGETS := AllLangHelp \
 	Zip \
 
 # build a generic gbuild target
-$(foreach target,$(gbuild_TARGETS),$(target)_% $(foreach module,$(gbuild_modules),$(target)_$(module)/%)) %.genpatch: bootstrap fetch
+$(foreach target,$(gbuild_TARGETS),$(target)_% $(foreach module,$(gbuild_modules),$(target)_$(module)/%)) UIConfig_modules/% %.genpatch: bootstrap fetch
 	$(MAKE) $(PARALLELISM_OPTION) $(GMAKE_OPTIONS) -f $(SRCDIR)/Makefile.gbuild $@
 
 #