ar71xx: Kernel board definition for PowerCloud CAP324

Kernel part of support for PowerCloud CAP324 Cloud AP.
The CAP324 Cloud AP was a device sold by PowerCloud Systems as hardware for
the CloudCommand service for 'cloud' based managment of large numbers
access points.

The CAP324 is a dual-band 802.11n wireless access point with 16MB flash
and 128MB RAM and single gigabit ethernet port. It can be powered via PoE
or a power adaptor.

Signed-off-by: Daniel Dickinson <openwrt@daniel.thecshore.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47938 3c298f89-4303-0410-b956-a3cf2f4a3e73