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>

SVN-Revision: 47942