wil6210: Fix kernel oops in reset flow

wil_reset() removes vring's
At the same time NAPI may be active performing Rx/Tx completion.
If this happens, Rx/Tx polling functions going to access already removed vrings

Make sure NAPI is idle and won't be started prior to vring removal.
For this, track NAPI enabled state

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Git-commit: 0fef1818d0888067f1231b05a08b2d56f017a169
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Liron Kuch <lkuch@codeaurora.org>