qcacld-3.0: Add legacy DP CFG items and APIs

Add the basic infra for legacy DP CFG items and the APIs
to be used from other components.

Change-Id: If7ad0e02c65e04ea13a308e680c9ba3b3d84ae25
CRs-Fixed: 2324099

cfg/cfg_all.h

@@ -44,6 +44,7 @@
 #include "wlan_pmo_cfg.h"
 #include "hdd_config.h"
 #include "hdd_dp_cfg.h"
+#include "cfg_legacy_dp.h"
 
 /* Maintain Alphabetic order here while adding components */
 #define CFG_ALL \
@@ -53,6 +54,7 @@
 	CFG_HDD_ALL \
 	CFG_HDD_DP_ALL \
 	CFG_IPA \
+	CFG_LEGACY_DP_ALL \
 	CFG_MLME_ALL \
 	CFG_NAN_ALL \
 	CFG_P2P_ALL \