ar71xx: Image generation for PowerCloud CR3000 Cloud Router

ar71xx: Image generation for PowerCloud CR3000 Cloud Router

Image generation part of support for PowerCloud CR3000.  The CR3000 is
a 802.11n 2.4 GHz wireless router with 8MB flash, 64MB RAM,
a four port fast ethernet switch, and a fast ethernet wan port which
was sold by PowerCloud Systems as hardware for the Skydog
cloud-managed router service.

Signed-off-by: Daniel Dickinson <openwrt@daniel.thecshore.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47942 3c298f89-4303-0410-b956-a3cf2f4a3e73