staging: vt6656: mac80211 conversion: add key functions

Create vnt_key_init_table to replace KeyvInitTable.

Create vnt_set_keymode to handle key setting operations with five different
modes VNT_KEY_DEFAULTKEY, VNT_KEY_GROUP_ADDRESS, VNT_KEY_ALLGROUP, VNT_KEY_GROUP
and VNT_KEY_PAIRWISE. VNT_KEY_ONFLY and VNT_KEY_ONFLY_ALL are for when
key latching in driver is not required.

Create vnt_set_keys to handle mac80211 key cipher modes, four modes are
supported WLAN_CIPHER_SUITE_WEP40, WLAN_CIPHER_SUITE_WEP104, WLAN_CIPHER_SUITE_TKIP
and WLAN_CIPHER_SUITE_CCMP.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>