ar7: enable the low-memory feature flag

Most ar7 devices have only 16 MiB RAM, so select low_mem to give them
a chance to work.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

SVN-Revision: 41532

target/linux/ar7/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 ARCH:=mipsel
 BOARD:=ar7
 BOARDNAME:=TI AR7
-FEATURES:=squashfs atm
+FEATURES:=squashfs atm low_mem
 MAINTAINER:=Florian Fainelli <florian@openwrt.org>
 SUBTARGETS:=generic ac49x