Remove $(TIRPCINC) from all Makefile.am files - it no longer exists

Also, restructure some of the dependencies in the lib/tt binaries.  We
will link with libtt (which will include libtirpc as a dependency),
and XTOOLLIB - all the right X11 stuff without needing to add it to
every OS.  Removed several uneeded OS specializations ("if LINUX",
etc) as a result.

cde/programs/dtspcd/Makefile.am

@@ -2,7 +2,7 @@ MAITAINERCLEANFILES = Makefile.in
 
 bin_PROGRAMS = dtspcd
 
-dtspcd_CFLAGS = $(TIRPCINC) -DCDE_CONFIGURATION_TOP=\"${prefix}\" \
+dtspcd_CFLAGS = -DCDE_CONFIGURATION_TOP=\"${prefix}\" \
 		-DCDE_INSTALLATION_TOP=\"$(CDE_INSTALLATION_TOP)\" \
 		$(DT_INCDIR)