qcacmn: Add support to process v2 fw2wbm completion structure

FW has moved to using v2 HTT_FW2WBM message format for Tx completions
Add corresponding change on Host.
Add missing code to free Tx descriptors for few HTT completion types
Also change the descriptor pool lock to spinlock_bh since transmit path
and completions typically run in tasklet/softirq context

Change-Id: I024d44243f95907f19086225f0f02a5cd64f4508
CRs-Fixed: 2068155
2 files changed