hostap_cs: Enable shared interrupts

The hostap_cs driver is programmed for exclusive rather that shared
interrupts.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-and-Tested-by: Jack Schneider <puck@dp-indexing.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>