iwlwifi: refactor rx register initialization

The patch adds HW bug W/A FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY so that we
can enable again interrupt coalescing. It also uses named constants for
open code.

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-csr.h b/drivers/net/wireless/iwlwifi/iwl-csr.h
index 52629fb..662edf4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-csr.h
+++ b/drivers/net/wireless/iwlwifi/iwl-csr.h
@@ -64,7 +64,7 @@
 #define CSR_BASE    (0x000)
 
 #define CSR_HW_IF_CONFIG_REG    (CSR_BASE+0x000) /* hardware interface config */
-#define CSR_INT_COALESCING      (CSR_BASE+0x004) /* accum ints, 32-usec units */
+#define CSR_INT_COALESCING     (CSR_BASE+0x004) /* accum ints, 32-usec units */
 #define CSR_INT                 (CSR_BASE+0x008) /* host interrupt status/ack */
 #define CSR_INT_MASK            (CSR_BASE+0x00c) /* host interrupt enable */
 #define CSR_FH_INT_STATUS       (CSR_BASE+0x010) /* busmaster int status/ack*/