wil6210: drop Rx packets with L2 error indication from HW

Due to recent change in FW, driver will be notified of corrupted Rx
packets (e.g. MIC error).
Drop such packets before they are delivered to network stack.

Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>