mwl8k: Wake up queues in mwl8k_start

If queues are stopped in mwl8k_stop,
these should be started in mwl8k_start

Signed-off-by: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: Yogesh Powar <yogeshp@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>