wil6210: fix locking in wmi_call

Switch from spin_lock to spin_lock_irqsave, because
wmi_ev_lock is used inside interrupt handler.

Change-Id: Ic3a5b3ab28b741f5fd1937757f6e6cd2fb8474b9
Signed-off-by: Lior David <liord@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Git-commit: dc57731dbd535880fe6ced31c229262c34df7d64
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


Signed-off-by: Maya Erez <merez@codeaurora.org>