qcacmn: Increase status size for HTT WBM completion v3

In beryllium DP, htt_tx_wbm_completion_v3 is used in which
20B are used by host and only 16B is assigned to the htt tx
status.
To fix this, increase the macro HAL_TX_COMP_HTT_STATUS_LEN
to 20 bytes.

Change-Id: I973ba1f8118488089cd6d6baac7fd589886c2164
CRs-Fixed: 3199031