This patch adds RX work queue support to mwifiex.
Packets received are queued to internal queue which are then
processed by scheduling a work item for RX process.

RX work is enabled only on SMP systems.
Reviewed-by: NJames Cameron <quozl@laptop.org>
Signed-off-by: NAvinash Patil <patila@marvell.com>
Signed-off-by: NMarc Yang <yangyang@marvell.com>
Signed-off-by: NCathy Luo <cluo@marvell.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>