staging: rtl8712: remove struct rtl_ieee80211_ht_cap and ieee80211_ht_addt_info

struct 'ieee80211_ht_addt_info' is unused and can be removed.

struct 'rtl_ieee80211_ht_cap' can be replaced by 'ieee80211_ht_cap'
defined in <linux/ieee80211.h> which has the same layout.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/4291cb10744457cc12c89fc9fd414c37d732bc9d.1617911201.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>