qcacmn: add rx_buffer_size to softumac case

add wlan_cfg_ctx in wlan_cfg_soc_attach for WLAN_SOFTUMAC_SUPPORT case
for compatibility with specific chipsets.

Change-Id: Icd1bbe85182d6baf1e25dceed0b45994aa9f55fc
CRs-Fixed: 3619315

wlan_cfg/wlan_cfg.c

@@ -4189,6 +4189,7 @@ wlan_cfg_soc_attach(struct cdp_ctrl_objmgr_psoc *psoc)
 	wlan_soc_tx_packet_inspect_attach(psoc, wlan_cfg_ctx);
 	wlan_soc_local_pkt_capture_cfg_attach(psoc, wlan_cfg_ctx);
 	wlan_soc_umac_reset_cfg_attach(psoc, wlan_cfg_ctx);
+	wlan_cfg_ctx->rx_buffer_size = cfg_get(psoc, CFG_DP_RX_BUFFER_SIZE);
 	return wlan_cfg_ctx;
 }