luci-app-diag-devinfo: mark broken due to dependencies

Mark luci-app-diag-devinfo @BROKEN as it has several failing dependencies:

Four dependencies from "oldpackages":
 httping, mac-to-devinfo, smap-to-devinfo, netdiscover-to-devinfo

One dependency from "abandoned":
 smap

(netdiscover is currently ok in trunk, but not in 15.05.)

Reference to Luci issue #523.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>