[freeradius2]: move into it's own submenu, add option to build without openssl

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>


git-svn-id: svn://svn.openwrt.org/openwrt/packages@39790 3c298f89-4303-0410-b956-a3cf2f4a3e73