build: modify default ARFLAGS / .a target

remove 'u' and specify all objects to allow objects with the same
basename to be added and a incremental rebuild to succeed

fixes issue #1067

Change-Id: Id0ebc89be826a026f1bbf21b4e32a2b1af45154d
diff --git a/build/make/Makefile b/build/make/Makefile
index 149647b..3081a92 100644
--- a/build/make/Makefile
+++ b/build/make/Makefile
@@ -287,7 +287,7 @@
 # for creating them.
 $(1):
 	$(if $(quiet),@echo "    [AR] $$@")
-	$(qexec)$$(AR) $$(ARFLAGS) $$@ $$?
+	$(qexec)$$(AR) $$(ARFLAGS) $$@ $$^
 endef
 
 define so_template
diff --git a/build/make/configure.sh b/build/make/configure.sh
index 9b6d820..12b9949 100644
--- a/build/make/configure.sh
+++ b/build/make/configure.sh
@@ -428,7 +428,7 @@
 
 CFLAGS  = ${CFLAGS}
 CXXFLAGS  = ${CXXFLAGS}
-ARFLAGS = -rus\$(if \$(quiet),c,v)
+ARFLAGS = -crs\$(if \$(quiet),,v)
 LDFLAGS = ${LDFLAGS}
 ASFLAGS = ${ASFLAGS}
 extralibs = ${extralibs}