ath10k: rename WMI_CMD_UNDEFINED

Rename WMI_CMD_UNDEFINED to WMI_CMD_UNSUPPORTED. This is more
accurate here. Also return -EOPNOTSUPP instead of -EINVAL in
wmi_cmd_send().

Signed-off-by: Bartosz Markowski <bartosz.markowski@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath10k/wmi.h b/drivers/net/wireless/ath/ath10k/wmi.h
index 7692c14..78c991a 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.h
+++ b/drivers/net/wireless/ath/ath10k/wmi.h
@@ -359,7 +359,7 @@
 #define WMI_CMD_GRP(grp_id) (((grp_id) << 12) | 0x1)
 #define WMI_EVT_GRP_START_ID(grp_id) (((grp_id) << 12) | 0x1)
 
-#define WMI_CMD_UNDEFINED 0
+#define WMI_CMD_UNSUPPORTED 0
 
 /* Command IDs and command events for MAIN FW. */
 enum wmi_cmd_id {