qcacmn: WMI support added for sifs_trigger interval config

FR: TDMA Support for Wave2 Radios (host support)
Added a wmi cmd for configuring the interval between successive sifs
trigger frames given by the user app. Added a separate wmi cmd instead
of wmi param with reference to further scope.

Change-Id: Ifa778a761e3495ef7abab5f63a49661b307034ae
CRs-Fixed: 2330484
3 files changed