mwifiex: fix system hang problem after resume

On some platforms, driver is unable to wakeup firmware after system resume
due to a problem at MMC subsystem. Triggering card reset in this case has
a race with card removal from MMC which causes system hang. This patch
resolves the problem by not triggering card reset.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>