brcmsmac: Remove the repeated declaration

Function 'brcms_c_stf_phy_txant_upd' are declared twice, remove
the repeated declaration.

Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1621844443-38290-1-git-send-email-zhangshaokun@hisilicon.com

drivers/net/wireless/broadcom/brcm80211/brcmsmac/stf.h

@@ -29,7 +29,6 @@ void brcms_c_stf_ss_update(struct brcms_c_info *wlc, struct brcms_band *band);
 void brcms_c_stf_phy_txant_upd(struct brcms_c_info *wlc);
 int brcms_c_stf_txchain_set(struct brcms_c_info *wlc, s32 int_val, bool force);
 bool brcms_c_stf_stbc_rx_set(struct brcms_c_info *wlc, s32 int_val);
-void brcms_c_stf_phy_txant_upd(struct brcms_c_info *wlc);
 void brcms_c_stf_phy_chain_calc(struct brcms_c_info *wlc);
 u16 brcms_c_stf_phytxchain_sel(struct brcms_c_info *wlc, u32 rspec);
 u16 brcms_c_stf_d11hdrs_phyctl_txant(struct brcms_c_info *wlc, u32 rspec);