ath5k: Put core clock initialization on a new function

* Handle all usec parameters in one function. It's much cleaner
 this way.

 Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>

Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/phy.c

@@ -1235,7 +1235,6 @@ static int ath5k_hw_channel(struct ath5k_hw *ah,
 	}
 
 	ah->ah_current_channel = channel;
-	ath5k_hw_set_clockrate(ah);
 
 	return 0;
 }