staging: r8188eu: remove rtw_freq2ch()

Function rtw_freq2ch() is not used, remove it.
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210922200420.9693-18-straube.linux@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_rf.c

@@ -53,20 +53,3 @@ u32 rtw_ch2freq(u32 channel)
 
 	return freq;
 }
-
-u32 rtw_freq2ch(u32 freq)
-{
-	u8	i;
-	u32	ch = 0;
-
-	for (i = 0; i < ch_freq_map_num; i++) {
-		if (freq == ch_freq_map[i].frequency) {
-			ch = ch_freq_map[i].channel;
-				break;
-		}
-	}
-	if (i == ch_freq_map_num)
-		ch = 1;
-
-	return ch;
-}

drivers/staging/r8188eu/include/rtw_rf.h

@@ -121,6 +121,5 @@ enum rt_rf_type_def {
 };
 
 u32 rtw_ch2freq(u32 ch);
-u32 rtw_freq2ch(u32 freq);
 
 #endif /* _RTL8711_RF_H_ */