pcmcia: convert ssb pcmcia driver to use new CIS helpers

SSB is a prime example of how to make use of the new CIS helpers.

CC: Michael Buesch <mb@bu3sch.de>
Acked-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>