Add a generic framework (wlan_cfg) for all configuration parameters
(eg.number of tx/rx rings) used by DP. Define all the parameters
as macro constants. We will later enhance wlan_cfg framework to
read these parameters from device tree file or ini file and populate
in DP config structures.
CRs-Fixed: 1073253
Change-Id: I7e4ddadb64006d17399acb68f92cf17fe23a98e2
