ath10k: workaround corrupted htt rx events

qca6174 WLAN.RM.2.0-00073 firmware uses full rx
reordering offload and delivers Rx via a new HTT
event. The event however is incorrectly generated
in firmware and becomes overly long (with trailing
garbage). This was hitting defined CE buffer limit
that was programmed to the device and caused
device to crash upon busier Rx traffic.

Increasing the CE buffer limit for HTT Rx pipe to
2KBytes seems to be enough to workaround this
problem.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>