iwinfo: make 'type' visible in wrapped iwinfo

There are several cases within 'luci' that attempt to access the interface
'type' from within the 'type' specific meta tables; however, 'type' is not
currently available there.  Replicate the common metadata in the 'type'
specific meta tables.

Signed-off-by: Nathan Hintz <nlhintz@hotmail.com>

SVN-Revision: 38448