liteos产物链接时全部使用.a，不再支持.o

Signed-off-by: i-wangliangliang <willfox@126.com>
Change-Id: Ifef5af899abdfead705117ab8620d29a252e9d06

toolchain/iccarm_link_helper.sh

@@ -19,6 +19,7 @@ ret=""
 for obj in "$@"; do
     case "${obj}" in
     *.a) ret="${ret} --whole_archive ${obj}" ;;
+    *.o) ret="${ret}" ;;
     *) ret="${ret} ${obj}" ;;
     esac
 done