qcacmn: Update no. of DWORDs for htt_tx_msdu_desc_ext2_t

This change is to update no. of dwords for htt_tx_msdu_desc_ext2_t
as new dwords have to be added by FW to pass
rx buffer address info to support opt_dp_ctrl.

Change-Id: I3edb0a32a1e340d715c00776254ab50aca93c4e0
CRs-Fixed: 3717471