broadcom-diag: add support for the ASUS RT-N12

This adds button and led info, which I determined
by manually poking the gpio values.

Signed-off-by: Josh Stone <cuviper@gmail.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37655 3c298f89-4303-0410-b956-a3cf2f4a3e73