kernel: disbale HAMRADIO in generic config

kernel: disbale HAMRADIO in generic config

HAMRADIO enabled in all generic configs, but no one platform directly
use related drivers/protocols. This symbol is only used for kmod-ax25
package modules. Furthermore, half of platforms explicitly disables
this symbol, what silently disables build of modules for kmod-ax25
package.

So disable HAMRADIO by-default in generic config, add it to kmod-ax25
package and remove it from platform specific configs.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44613 3c298f89-4303-0410-b956-a3cf2f4a3e73