qcacld-3.0: Maintain frame count per txq-group

1) Add function: ol_tx_update_grp_frm_count() to maintain count of frames
per group.
2) Call ol_tx_update_grp_frm_count() from ol_tx_enqueue(),
ol_tx_dequeue() and ol_tx_queue_free().

Change-Id: If1b07ea5bbdcbc6ad6d0c91e6b2060c4264b9472
CRs-fixed: 2246206
3 files changed