Modified the Makefiles to include a "make uninstall" to remove an
installed PDK.
diff --git a/Makefile.in b/Makefile.in
index a4e8a02..29ee1a3 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -30,6 +30,10 @@
 # 	clean up all files generated by 'make' and remove
 #	all log files.
 #
+# make uninstall
+#
+#	remove the installed PDKs.
+#
 #---------------------------------------------------
 #
 # The following definitions are tied to the contents
@@ -49,6 +53,7 @@
 
 TECHS_ALL = $(addprefix tech_,$(TECHS))
 TECHS_INSTALL = $(addprefix install-,$(TECHS))
+TECHS_UNINSTALL = $(addprefix uninstall-,$(TECHS))
 TECHS_CLEAN = $(addprefix clean-,$(TECHS))
 TECHS_VERYCLEAN = $(addprefix veryclean-,$(TECHS))
 
@@ -60,6 +65,9 @@
 install: $(TECHS_INSTALL)
 	@echo $(DONE_MESSAGE)
 
+uninstall: $(TECHS_UNINSTALL)
+	@echo $(DONE_MESSAGE)
+
 clean: $(TECHS_CLEAN)
 	@echo $(DONE_MESSAGE)
 
@@ -80,6 +88,9 @@
 install-sky130:	sky130
 	(cd sky130 && ${MAKE} install)
 
+uninstall-sky130: sky130
+	(cd sky130 && ${MAKE} uninstall)
+
 clean-sky130:
 	(cd sky130 && ${MAKE} clean)