iwlwifi: mvm: fix build w/o CONFIG_THERMAL

Without CONFIG_THERMAL, the driver fails to link as it calls
iwl_mvm_send_temp_report_ths_cmd() unconditionally. Fix this
by making that function available, but do almost nothing but
send the empty firmware command to enable CT-kill reporting.

While at it, also fix that function itself to not error out
when the thermal zone hasn't been initialized, but instead
just send the empty firmware command in this case as well.

Fixes: 242d9c8b ("iwlwifi: mvm: use FW thermal monitoring regardless of CONFIG_THERMAL")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/intel/iwlwifi/mvm/tt.c

@@ -555,16 +555,19 @@ static int compare_temps(const void *a, const void *b)
 	return ((s16)le16_to_cpu(*(__le16 *)a) -
 		(s16)le16_to_cpu(*(__le16 *)b));
 }
+#endif
 
 int iwl_mvm_send_temp_report_ths_cmd(struct iwl_mvm *mvm)
 {
 	struct temp_report_ths_cmd cmd = {0};
-	int ret, i, j, idx = 0;
+	int ret;
+#ifdef CONFIG_THERMAL
+	int i, j, idx = 0;
 
 	lockdep_assert_held(&mvm->mutex);
 
 	if (!mvm->tz_device.tzone)
-		return -EINVAL;
+		goto send;
 
 	/* The driver holds array of temperature trips that are unsorted
 	 * and uncompressed, the FW should get it compressed and sorted
@@ -597,6 +600,7 @@ int iwl_mvm_send_temp_report_ths_cmd(struct iwl_mvm *mvm)
 	}
 
 send:
+#endif
 	ret = iwl_mvm_send_cmd_pdu(mvm, WIDE_ID(PHY_OPS_GROUP,
 						TEMP_REPORTING_THRESHOLDS_CMD),
 				   0, sizeof(cmd), &cmd);
@@ -607,6 +611,7 @@ int iwl_mvm_send_temp_report_ths_cmd(struct iwl_mvm *mvm)
 	return ret;
 }
 
+#ifdef CONFIG_THERMAL
 static int iwl_mvm_tzone_get_temp(struct thermal_zone_device *device,
 				  int *temperature)
 {