iwl3945: use hw_params.rx_buf_size

This patch makes 3945 use of hw_params.rx_buf_size instead of
IWL_RX_BUF_SIZE. It also renames IWL_RX_BUF_SIZE to IWL_RX_BUF_SIZE_3K
and moves rx buffer defines into iwl-fh.h.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.c b/drivers/net/wireless/iwlwifi/iwl-3945.c
index db7b949..8a378bd 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -2485,7 +2485,7 @@
 		return -ENOMEM;
 	}
 
-	priv->hw_params.rx_buf_size = IWL_RX_BUF_SIZE;
+	priv->hw_params.rx_buf_size = IWL_RX_BUF_SIZE_3K;
 	priv->hw_params.max_pkt_size = 2342;
 	priv->hw_params.max_rxq_size = RX_QUEUE_SIZE;
 	priv->hw_params.max_rxq_log = RX_QUEUE_SIZE_LOG;