ath10k: fix vdev stats for 10.4 firmware

Currently vdev stats displayed in fw_stats are applicable
only for TLV based firmware and fix it for 10.4 firmware
as of now. The vdev stats in 10.4 firmware is split into two
parts (vdev_stats, vdev_stats_extended). The actual stats
are captured only in extended vdev stats. In order to enable
vdev stats, appropriate feature bit will be set on extended
resource config. As FTM related counters are available only on
newer 10.4 based firmware, these counters will be displayed
only on valid data.

Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>