Makefile: introduce minimal target

"minimal" target will only build program used by
the test-suite.

The "all" target will build both release and debug.
The default target is "minimal"

Signed-off-by: Christopher Li <sparse@chrisli.org>
diff --git a/Makefile b/Makefile
index b012a49..92399c2 100644
--- a/Makefile
+++ b/Makefile
@@ -196,10 +196,10 @@
 INST_PROGRAMS += $(REL_PROGRAMS) \
 		 $(filter-out $(addprefix dbgbuild/,$(REL_PROGRAMS)),$(DBG_PROGRAMS))
 
-all: $(REL_PROGRAMS) sparse.pc
-
+minial: $(REL_PROGRAMS)
 release: $(PROGRAMS)
 debug: $(DBG_PROGRAMS)
+all: release debug sparse.pc
 
 all-installable: $(INST_PROGRAMS) $(LIBS) $(LIB_H) sparse.pc
 
@@ -278,7 +278,7 @@
 	fi
 	git archive --format=tar --prefix=sparse-$(VERSION)/ HEAD^{tree} | gzip -9 > sparse-$(VERSION).tar.gz
 
-check: all debug
+check: all
 	$(Q)cd validation && ./test-suite
 
 clean-check: