ath10k: Enable bundle tx compl for management frames in WCN3990

WCN3990 sends tx completion of multiple management
frames bundled together in a single event, if the
host driver exposes the support to handle this
bundled tx completion event. This reduces the number
of WMI events which are sent to the host driver by
the target.

Set the BUNDLE_TX_COMPL flag in the host capability
flags when host sends the wmi init command, to indicate
the host capability to handle bundled tx completion for
management frames.

Tested HW: WCN3990
Tested FW: WLAN.HL.2.0-01188-QCAHLSWMTPLZ-1

Signed-off-by: Rakesh Pillai <pillair@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>