ath11k: Move non-fatal warn logs to dbg level

During driver load below warn logs are printed in the console.
Since driver may not implement all wmi events sent by fw and
all of them are non-fatal, move this log to debug level to
remove un-necessary warn message on console.

[876.898735] ath11k_pci 0000:06:00.0: Unknown eventid: 0x16005
[879.283250] ath11k_pci 0000:06:00.0: Unknown eventid: 0x1d00a

No functional changes. Compile tested only.

Signed-off-by: Govind Singh <govinds@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1600948691-6901-1-git-send-email-govinds@codeaurora.org