pcmcia: ds: fix suspend/resume

PCMCIA suspend/resume no longer works since the commit mentioned below,
as the callbacks are no longer made.  Convert the driver to the new
dev_pm_ops, which restores the suspend/resume functionality.  Tested on
the arm arch Assabet platform.

Fixes: aa8e54b5

 ("PM / sleep: Go direct_complete if driver has no callbacks")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>