wifi: brcmsmac: ampdu: remove unused cb_del_ampdu_pars struct

struct cb_del_ampdu_pars was added in the initial commit 5b435de0
("net: wireless: add brcm80211 drivers") and its only usage was removed in
commit e041f65d

 ("brcmsmac: Remove internal tx queue").

Remove the structure definition now. This saves a few lines of code.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/fa3b190b6e9cba65ecc36fc93121c6ed8704f704.1714036681.git.christophe.jaillet@wanadoo.fr