ath10k: reduce number of peers to support peer stats feature

To enable per peer stats feature we are reducing the number of peers.
Firmware has introduced tx stats feature. We have memory limitation in
firmware to add these additional bytes.

These are the new variables introduced in the firmware.
========		=======================
Variable	      	Bytes required/per rate
========		=======================
TX success packets 	1
TX failed packets	1
Retry packets		1
Success bytes		2
TX failed bytes		2
Retry bytes		2
Tx duration		4
Rate			1
Bw and AMPDU flags	1
Total			16 (because of allocation in word pattern)

Firmware sends these tx_stats in pktlog.
If we consider 4 feedbacks at a time, Frimware need about ~1K memory for coding
and 8192 bytes required / per rate [ 4*16*128(peers)].
To accommodate this firmware needs to reduce 10 peers.

This fixes a firmware crash with firmware-5.bin_10.2.4.70.22-2.

Signed-off-by: Anilkumar Kolli <akolli@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>