qcacmn: Fix issue in green AP feature

Green AP feature for WIN allows the AP to go into power save mode
and leads to only a single chain being active.

In the current code, it is seen that the WMI API for enabling Green
AP feature is under "FEATURE_GREEN_AP" flag that is not defined for
WIN. This leads to trigger of dummy API that does no operation.

Replace "FEATURE_GREEN_AP" with proper flag "ATH_SUPPORT_GREEN_AP"
defined on WIN to enable Green AP feature.

Change-Id: I344e74c3753f1ef3b6d5d5a2bb1086c84f2ab84c
CRs-Fixed: 1074036
diff --git a/wmi_unified_api.c b/wmi_unified_api.c
index 3d9e185..8778598 100644
--- a/wmi_unified_api.c
+++ b/wmi_unified_api.c
@@ -251,7 +251,7 @@
 	return QDF_STATUS_E_FAILURE;
 }
 
-#ifdef FEATURE_GREEN_AP
+#if defined(FEATURE_GREEN_AP) || defined(ATH_SUPPORT_GREEN_AP)
 /**
  * wmi_unified_green_ap_ps_send() - enable green ap powersave command
  * @wmi_handle: wmi handle
@@ -277,7 +277,7 @@
 {
 	return 0;
 }
-#endif /* FEATURE_GREEN_AP */
+#endif /* FEATURE_GREEN_AP or ATH_SUPPORT_GREEN_AP*/
 
 /**
  * wmi_unified_pdev_utf_cmd() - send utf command to fw