The max bundle size support by firmware is 32, change it from 8 to 32
will help performance. This results in significant performance
improvement on RX path.

The real max rx bundle is decided in ath10k_htc_wait_target(),
it is the min value of HTC_HOST_MAX_MSG_PER_RX_BUNDLE and the value reported
from firmware. So this change shouldn't cause any regressions with other
hardware supported by ath10k.

Tested with QCA6174 SDIO with firmware WLAN.RMH.4.4.1-00017-QCARMSWPZ-1.
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>