pcmcia: use dev_pm_ops for class pcmcia_socket_class

Instead of requiring PCMCIA socket drivers to call various functions
during their (bus) resume and suspend functions, register an own
dev_pm_ops for this class. This fixes several suspend/resume bugs
seen on db1xxx-ss, and probably on some other socket drivers, too.

With regard to the asymmetry with only _noirq suspend, but split up
resume, please see bug 14334 and commit 9905d1b4 .

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>