cfg80211: remove double prototype

cfg80211_calculate_bitrate() is defined in the external
header file cfg80211.h now, so no need to keep it in
the internal one as well.

Signed-off-by: Johannes Berg <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

net/wireless/core.h

···
 		      struct wireless_dev *wdev, int freq,
 		      enum nl80211_channel_type channel_type);
 
-u16 cfg80211_calculate_bitrate(struct rate_info *rate);
-
 int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
 			   const u8 *rates, unsigned int n_rates,
 			   u32 *mask);