Change make to $(MAKE), patch by Hideki IWAMOTO
diff --git a/Makefile b/Makefile
index bfa7601..b99bb4f 100644
--- a/Makefile
+++ b/Makefile
@@ -148,7 +148,7 @@
 
 include/config.h: .config
 	@if [ ! -x ./scripts/config/conf ] ; then \
-	    make -C scripts/config conf; \
+	    $(MAKE) -C scripts/config conf; \
 	fi;
 	@./scripts/config/conf -o sysdeps/$(TARGET_OS)/Config.in
 
@@ -168,12 +168,12 @@
 # ---------------------------------------------------------------------------
 
 scripts/config/conf:
-	make -C scripts/config conf
+	$(MAKE) -C scripts/config conf
 	-@if [ ! -f .config ] ; then \
 		cp sysdeps/$(TARGET_OS)/defconfig .config; \
 	fi
 scripts/config/mconf:
-	make -C scripts/config ncurses conf mconf
+	$(MAKE) -C scripts/config ncurses conf mconf
 	-@if [ ! -f .config ] ; then \
 		cp sysdeps/$(TARGET_OS)/defconfig .config; \
 	fi