wil6210: treat "unhandled event" as warning instead of error

FW is allowed to generate WMI events that are not handled by this driver.
Treat such case as warning instead of error.

Change-Id: Ia789bd25484172ab4babd0894adca2f07bdd6458
Signed-off-by: Dedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-commit: a3ce5ccd50ee24313fa3e55d2cafc6da7dfcbe18
Git-repo: https://github.com/kvalo/ath.git


Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>