tools: fix "make distclean"

The original rule to target "distclean" in tools/Rules.mk was in effect
"make clean". It should be "make distclean".

However not all Makefiles in subdirectories have distclean target
defined. So this patch also adds a bunch of distclean targets to various
Makefiles. They only depend on clean target and don't have any actions
in most cases.

With the patch applied, following command outputs 0 results:

  find tools -name 'Makefile*' -exec grep -L 'distclean' {} \+ \
     | grep -v ocaml | grep -v libfsimage

Ocaml and libfsimage are known to have distclean defined in a dedicated
rules file.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

tools/debugger/gdbsx/Makefile

@@ -12,6 +12,10 @@ clean:
 	rm -f xg_all.a gx_all.a gdbsx
 	set -e; for d in xg gx; do $(MAKE) -C $$d clean; done
 
+.PHONY: distclean
+distclean: clean
+	set -e; for d in xg gx; do $(MAKE) -c $$d distclean; done
+
 .PHONY: install
 install: all
 	[ -d $(DESTDIR)$(SBINDIR) ] || $(INSTALL_DIR) $(DESTDIR)$(SBINDIR)

tools/debugger/gdbsx/gx/Makefile

@@ -11,6 +11,8 @@ all: gx_all.a
 clean:
 	rm -rf gx_all.a *.o .*.d
 
+.PHONY: distclean
+distclean: clean
 
 #%.o: %.c $(GX_HDRS) Makefile
 #	$(CC) -c $(CFLAGS) -o $@ $<

tools/debugger/gdbsx/xg/Makefile

@@ -33,3 +33,5 @@ xen-headers:
 clean:
 	rm -rf xen xg_all.a $(XG_OBJS)  .*.d
 
+.PHONY: distclean
+distclean: clean

tools/debugger/kdd/Makefile

@@ -16,6 +16,9 @@ kdd: $(OBJS)
 clean:
 	rm -f $(OBJS) $(DEPS) kdd
 
+.PHONY: distclean
+distclean: clean
+
 .PHONY: install
 install: all
 	[ -d $(DESTDIR)$(SBINDIR) ] || $(INSTALL_DIR) $(DESTDIR)$(SBINDIR)