iwlwifi: move BIOS MCC retrieval to common code

This will be used by more than MVM, so move it to iwlwifi

While at it, rename WRD_METHOD to the more appropriate
WRDD_METHOD and add some documentation.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.h b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.h
index d704d52..7249e5b 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.h
@@ -5,7 +5,8 @@
  *
  * GPL LICENSE SUMMARY
  *
- * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
+ * Copyright(c) 2008 - 2015 Intel Corporation. All rights reserved.
+ * Copyright(c) 2016        Intel Deutschland GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -93,4 +94,21 @@
 iwl_parse_nvm_mcc_info(struct device *dev, const struct iwl_cfg *cfg,
 		       int num_of_ch, __le32 *channels, u16 fw_mcc);
 
+#ifdef CONFIG_ACPI
+/**
+ * iwl_get_bios_mcc - read MCC from BIOS, if available
+ *
+ * @dev: the struct device
+ * @mcc: output buffer (3 bytes) that will get the MCC
+ *
+ * This function tries to read the current MCC from ACPI if available.
+ */
+int iwl_get_bios_mcc(struct device *dev, char *mcc);
+#else
+static inline int iwl_get_bios_mcc(struct device *dev, char *mcc)
+{
+	return -ENOENT;
+}
+#endif
+
 #endif /* __iwl_nvm_parse_h__ */