ar71xx: add support for hornet-ub-x2

The hornet-ub-x2 is hornet-ub variant with double more flash and ram.

Signed-off-by: Luka Perkov <luka@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37788 3c298f89-4303-0410-b956-a3cf2f4a3e73
uboot-envtools: add support for hornet-ub-x2

Signed-off-by: Luka Perkov <luka@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37789 3c298f89-4303-0410-b956-a3cf2f4a3e73