This supercedes the older patch ("cw1200: Don't perform SPI transfers in
interrupt context") that badly attempted to fix this problem.

This is a far simpler solution, which has the added benefit of
actually working.
Signed-off-by: NSolomon Peachy <pizza@shaftnet.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>