tools: Correct python building host tools

When we have python building tools for the host it will not check HOSTXX
variables but only XX variables, for example LDFLAGS and not
HOSTLDFLAGS.

Cc: Simon Glass <sjg@chromium.org>
Reported-by: NHeiko Schocher <hs@denx.de>
Fixes: 1905c8fc ("build: Always build the libfdt python module")
Signed-off-by: NTom Rini <trini@konsulko.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Tested-by: NSimon Glass <sjg@chromium.org>
Tested-by: NHeiko Schocher <hs@denx.de>

tools/Makefile

@@ -117,7 +117,8 @@ _libfdt.so-sharedobjs += $(LIBFDT_OBJS)
 libfdt:
 
 tools/_libfdt.so: $(patsubst %.o,%.c,$(LIBFDT_OBJS)) tools/libfdt_wrap.c
-	python $(srctree)/lib/libfdt/setup.py "$(_hostc_flags)" $^
+	LDFLAGS="$(HOSTLDFLAGS)" python $(srctree)/lib/libfdt/setup.py \
+		"$(_hostc_flags)" $^
 	mv _libfdt.so $@
 
 tools/libfdt_wrap.c: $(srctree)/lib/libfdt/libfdt.swig