ath5k: Update RF Buffer handling

 * Use the new way to modify rf buffer and put some rf buffer
   documentation on rfbufer.h

 * Merge all rf regs functions to one

 * Sync with legacy HAL and Sam's HAL

 * Set gain_F settings so that gain_F optimization engine works
   on RF5111/RF5112 (note that both HALs only use step 0 for RF5111
   and they don't use gain_F optimization for this chip, code is
   there but is never used)

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

Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath5k/reset.c b/drivers/net/wireless/ath5k/reset.c
index f7ce80e..40cf4c7 100644
--- a/drivers/net/wireless/ath5k/reset.c
+++ b/drivers/net/wireless/ath5k/reset.c
@@ -600,7 +600,7 @@
 		/*
 		 * Write RF registers
 		 */
-		ret = ath5k_hw_rfregs(ah, channel, mode);
+		ret = ath5k_hw_rfregs_init(ah, channel, mode);
 		if (ret)
 			return ret;