iwlwifi: mvm: BT Coex - always set mandatory fields

The firmware always expects the Coex Mode to be set.
Moreover, the firmware expects bit 0 is the valid bits to
be set all the times.
I misunderstood the API and didn't set these bits when
commands are sent to update the paramters of the Coex. As
a result, the firmware understood that the BT Coex was
disabled (Coex mode = 0) and ignored all the updates (valid
bit 0 clear).

Fix that.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/mvm/fw-api-bt-coex.h b/drivers/net/wireless/iwlwifi/mvm/fw-api-bt-coex.h
index acb32f4..4ea5e24 100644
--- a/drivers/net/wireless/iwlwifi/mvm/fw-api-bt-coex.h
+++ b/drivers/net/wireless/iwlwifi/mvm/fw-api-bt-coex.h
@@ -82,6 +82,8 @@
  * @BT_USE_DEFAULTS:
  * @BT_SYNC_2_BT_DISABLE:
  * @BT_COEX_CORUNNING_TBL_EN:
+ *
+ * The COEX_MODE must be set for each command. Even if it is not changed.
  */
 enum iwl_bt_coex_flags {
 	BT_CH_PRIMARY_EN		= BIT(0),
@@ -103,6 +105,8 @@
 
 /*
  * indicates what has changed in the BT_COEX command.
+ * BT_VALID_ENABLE must be set for each command. Commands without this bit will
+ * discarded by the firmware
  */
 enum iwl_bt_coex_valid_bit_msk {
 	BT_VALID_ENABLE			= BIT(0),