ath11k: Fix rx_filter flags setting for per peer rx_stats

ath11k: Fix rx_filter flags setting for per peer rx_stats

Rx_filter flags are set with default filter flags during
wifi up/down sequence even though the 'ext_rx_stats' debugfs
is enabled as 1. So, that we are not getting proper per peer
rx_stats.
Hence, fixing this by setting the missing rx_filter when
ext_rx_stats is already set/enabled.

Signed-off-by: Maharaja Kennadyrajan <mkenna@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1586538405-16226-3-git-send-email-mkenna@codeaurora.org