atheros: move bus ops to ath_common

This is the last part to make ath9k hw code core driver agnostic.
I believe ath9k_htc can now use use the hw code unmodified.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/eeprom_4k.c b/drivers/net/wireless/ath/ath9k/eeprom_4k.c
index c2ac85c..2a27b1d 100644
--- a/drivers/net/wireless/ath/ath9k/eeprom_4k.c
+++ b/drivers/net/wireless/ath/ath9k/eeprom_4k.c
@@ -41,7 +41,7 @@
 	}
 
 	for (addr = 0; addr < SIZE_EEPROM_4K; addr++) {
-		if (!ath9k_hw_nvram_read(ah, addr + eep_start_loc, eep_data)) {
+		if (!ath9k_hw_nvram_read(common, addr + eep_start_loc, eep_data)) {
 			ath_print(common, ATH_DBG_EEPROM,
 				  "Unable to read eeprom region \n");
 			return false;
@@ -66,7 +66,7 @@
 
 
 	if (!ath9k_hw_use_flash(ah)) {
-		if (!ath9k_hw_nvram_read(ah, AR5416_EEPROM_MAGIC_OFFSET,
+		if (!ath9k_hw_nvram_read(common, AR5416_EEPROM_MAGIC_OFFSET,
 					 &magic)) {
 			ath_print(common, ATH_DBG_FATAL,
 				  "Reading Magic # failed\n");