iwlwifi: mvm: debugfs: add an option to set antennas for scan command

Add an option to set rx antennas for the scan command from debugfs.
Create a file called ant_rxchain in the mvm debugfs directory.
To choose antennas, write a number between 1-7 to ant_rxchain.
Write 1 for A, 2 for B, 3 for AB and so on.

Signed-off-by: Oren Givon <oren.givon@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index 2becb09..0d3bdef 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -470,6 +470,9 @@
 	enum iwl_scan_status scan_status;
 	struct iwl_scan_cmd *scan_cmd;
 
+	/* rx chain antennas set through debugfs for the scan command */
+	u8 scan_rx_ant;
+
 	/* Internal station */
 	struct iwl_mvm_int_sta aux_sta;