pcmcia: remove remaining in-kernel pcmcia_get_configuration_info() users

Remove the three remaining pcmcia_get_configuration_info() users:
- pcmciamtd is marked broken anyway.
- serial_cs.c can access the relevant structs directly
- ipwireless didn't use the output

CC: linux-serial@vger.kernel.org
CC: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>