ssb-pcmcia: IRQ and DMA related fixes

Here come some IRQ and DMA related fixes for the ssb PCMCIA-host code.
Not much to say, actually. I think the patch explains itself.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>