wifi: ti: Avoid a hundred -Wflex-array-member-not-at-end warnings

-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.

Remove unused flexible-array members in multiple structures, and fix
a hundred -Wflex-array-member-not-at-end warnings[1] in
drivers/wireless/ti/

Link: https://gist.github.com/GustavoARSilva/fbf63c114d01319bbd19baf95b4d704b [1]
Link: https://github.com/KSPP/linux/issues/202
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/ZgDcwIgxkhs6ZVdY@neat

drivers/net/wireless/ti/wl1251/cmd.h

@@ -89,8 +89,6 @@ enum wl1251_commands {
 struct wl1251_cmd_header {
 	u16 id;
 	u16 status;
-	/* payload */
-	u8 data[];
 } __packed;
 
 struct  wl1251_command {

drivers/net/wireless/ti/wl1251/wl12xx_80211.h

@@ -65,7 +65,6 @@ struct ieee80211_header {
 	u8 sa[ETH_ALEN];
 	u8 bssid[ETH_ALEN];
 	__le16 seq_ctl;
-	u8 payload[];
 } __packed;
 
 struct wl12xx_ie_header {

drivers/net/wireless/ti/wlcore/cmd.h

@@ -208,8 +208,6 @@ enum cmd_templ {
 struct wl1271_cmd_header {
 	__le16 id;
 	__le16 status;
-	/* payload */
-	u8 data[];
 } __packed;
 
 #define WL1271_CMD_MAX_PARAMS 572

drivers/net/wireless/ti/wlcore/wl12xx_80211.h

@@ -66,7 +66,6 @@ struct ieee80211_header {
 	u8 sa[ETH_ALEN];
 	u8 bssid[ETH_ALEN];
 	__le16 seq_ctl;
-	u8 payload[];
 } __packed;
 
 struct wl12xx_ie_header {