ath10k: demote chan info without scan request warning

Some devices/firmwares cause this to be printed every 5-15 seconds,
though it has no impact on functionality. Demote this to a debug
message.

I see this on SDM845 and MSM8998 platforms, specifically the OnePlus 6 devices,
PocoPhone F1 and OnePlus 5.  On the OnePlus 6 (SDM845) we are stuck with the
following signed vendor fw:

[    9.339873] ath10k_snoc 18800000.wifi: qmi chip_id 0x30214 chip_family 0x4001 board_id 0xff soc_id 0x40030001
[    9.339897] ath10k_snoc 18800000.wifi: qmi fw_version 0x20060029 fw_build_timestamp 2019-07-12 02:14 fw_build_id QC_IMAGE_VERSION_STRING=WLAN.HL.2.0.c8-00041-QCAHLSWMTPLZ-1

The OnePlus 5 (MSM8998) is using firmware:

[ 6096.956799] ath10k_snoc 18800000.wifi: qmi chip_id 0x30214 chip_family 0x4001 board_id 0xff soc_id 0x40010002
[ 6096.956824] ath10k_snoc 18800000.wifi: qmi fw_version 0x1007007e fw_build_timestamp 2020-04-14 22:45 fw_build_id QC_IMAGE_VERSION_STRING=WLAN.HL.1.0.c6-00126-QCAHLSWMTPLZ-1.211883.1.278648.

Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.2.0.c8-00041-QCAHLSWMTPLZ-1
Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.1.0.c6-00126-QCAHLSWMTPLZ-1.211883.1.278648

Signed-off-by: Caleb Connolly <caleb@connolly.tech>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210522171609.299611-1-caleb@connolly.tech